yeah i think a lot of this is based on a settler brained distortion of decolonization/landback as like reverse colonialism with the ultimate goal of instating some kind of bizarro ethnostate for the colonized. literally just isn't what it's about. especially in the US where we don't have the same kind of hyper violent concentration camp thing happening (anymore) revenge really doesn't seem to be a priority of any Indigenous people.
uncritical support to ewichuu for being so nice she actually reads my rambling
honestly not versed enough in the history of the USSR to get into it, although the PRC uses a similar system and they haven't collapsed like that. i've heard a big issue the USSR faced was failing to transition power to a younger generation, in part because the october revolutionaries were just that popular. socialism is under constant threat, and in a revolution or being encircled by capitalist imperialism there's a lot of very important, high stakes decisions to make. someone has to make those calls. if we kick it down to direct referendums, someone's got to write the options. can kind of just keep going down the line until we get to the point of everyone responds to the issue how they see fit, and yeah that's a lot of choice but is the choice even meaningful at that point? it's the accountability problem again. being bound by authority doesn't always feel great but if it goes both ways that's a type of power. that's kind of the point of representatives to me, if there isn't authority somewhere then that authority retreats into social dynamics, and if that authority isn't being responsible you've got to navigate a much more opaque system without clear rules.
So i think it's important to remember that the people voting those early liberals were envisioning were all white male landowners, and if there's any group of people the system is actually accountable to, what do they tend to have in common?
The most powerful politicians rarely have to be disciplined by capital either, because it's not as simple as just lying, getting into the position to even try for those elections requires working your way through a political system designed to produce liberal capitalist politicians. The more powerful a position, the more impossible it is to simply hide who you are and come out unchanged. It's really quite solid for maintaining the interests of a certain class.
Why not have a similar system but for a communist party? I think requiring years to decades of consistent accomplishment within an explicitly communist and worker centric party that you're accountable to is a pretty good way to select people for powerful and important jobs. Sure some rightists could lie their way through, but they shouldn't ever get that far without going mask off, and like leftists in the democratic party someone going against the ideals in a lower level position can only do so much before getting purged or brought in line.
Eliminating positions of power does sound nice, and it should be done as much as feasible, but outright eliminating formally structured power doesn't eliminate social power. I think it's more practical and realistic to intentionally design a system of power to minimize the effect of historical oppressions and biases than it is to abolish formalized power and rely on everyone being self aware enough to not immediately reinvent the oppressions we've been taught.
Marxists that aren't ML might not agree with Lenin, they might agree with Lenin but think his ideas were distorted, they might not be particularly interested in Lenin, they might still be working out their opinion on him. It's also entirely possible that they're choosing to id as a Marxist bc that's less risky in their situation. Talking about tendencies can be a lot like talking abt gender or sexuality; language is a strategy.
i think what people are usually talking about when they talk about wanting democracy is a combination of having input on decisions, and leaders being accountable to democratically decided decisions. Since we're so thoroughly disempowered under liberal bourgeois democracy it's very attractive to insist on everyone having a say and having power, but that creates a problem with the second part of democracy, accountability. What good is having the ability to be heard and influence decision making when those decisions aren't all that binding? And how is accountability supposed to work without some degree of centralization? While our present system certainly does use centralization to disempower us, it's important to note how the decentralized aspects subvert people's will too. The United States system is very influenced by a desire to maintain minority rule, and decentralization is a very important tool for accomplishing that by removing powers from ostensibly democratically accountable bodies (supreme court), and granting a certain level of independence to states and abridging the central govts ability to impose on state governments.
I know wanting more accountability to central power is kind of strange, especially coming when i'm a member of a minority group that the majority is allegedly prejudiced against, but i've come to the point of having full faith that my interests are the same as the proletariat's class interests. It's easy to get caught up in an elitist fear of the masses at first, but i don't think a true dictatorship of the proletariat has any real reason oppress me in any way that i'd care about, while a dictatorship of the bourgeois would. This is of course rests on the idea that state power itself or certain ways of doing democracy don't have a class character, which is where anarchists will disagree, but i'd say look up anarchist style consensus decision making and the liberum veto and compare.
any Marxist-Leninist should be a Marxist, it's kind of a squares and rectangles situation. declaring yourself a Marxist-Leninist is to my understanding a statement that Lenin and the ML states after him advanced Marxism through theory and practice and their findings are applicable and necessary to Marxist practice now. Some people go further into being Marxist-Leninist-Maoists, claiming Mao advanced Marxism and learned lessons broadly applicable outside of the context of China.
Saying anarchists want no systems at all is unfair to them i think, although it's such a decentralized ideology that some anarchists certainly would say that. There's a fundamental agreement on working towards communism as a classless, stateless society between marxism and anarchism. The fundamental disagreement in my view is that marxism views communism and socialism as the result of proletarian political self consciousness and actualization by becoming aware of their own interests and ultimately taking state power (this is Lenin's big contribution, and why it's easy to find anarchists trying to reclaim Marx for anarchism but never Lenin), whereas anarchism has more of a "the classless stateless society was inside us the whole time" thing, where the state and hierarchy are abridging our natural tendency towards communism. You can kinda see this in contemporary anarchist's affinity for David Graeber, but it goes way back to Kropotkin's work on mutual aid and probably even older. A lot of popular anarchist arguments point out that people often organize themselves without the threat of violence, e.g. queueing.
i don't think i could really tell you what libertarian socialists want exactly, i think they're generally motivated by self interest (wanting health care, to be exploited less, you know the good kind of self interest) so sort of like the marxist class interest thing, but are also suspicious of the discipline and to be honest, repression (of the bourgeois) implied by ML which is where the anarchist influence comes in. Usually manifests in wanting socialist systems that are explicitly democratic, in contrast to the socialist systems that have already been tried, and a really common critique is that those systems were not democratic bc they were too centralized, bc more decentral = more democracy is an ideological proposition that's just kind of accepted in the west. Arguing over whether the USSR, PRC, and so on was really democratic and what democracy actually means is ofc the usual response.
libertarian and anarchist were basically synonymous for the beginning of the 20th century, idk if libertarian anarchism is something anyone identifies with except for maybe a few ancaps.
Libertarian socialism is kind of a centrist fusion of anarchism and marxism that's afaik mostly defined by liking socialism but being against "authoritarianism".
Tankie started out as a pejorative for a type of Marxist-Leninist, although it's been getting way less specific in the last couple of years. At this point it's basically aimed at anyone who refuses to satisfactorily denounce the USSR, China, or basically any geopolitical rival of the US and NATO. i like this explanation a lot: https://redsails.org/tankies/
I mostly consider myself an ML as much as that means anything, but lean into self IDing as a tankie more than i probably should just bc i think sincere internationalism is nonnegotiable for good left politics in the imperial core and the dominant narratives around the people and states that'll get you called a tankie for opposing are racist as fuck when you get down to it.
tbf some of the anarchists i've hung around with would probably get called tankies online for their takes on the DPRK, so it's not ML exclusive, but i'm kind of doubtful libsoc or any other ideology concerned with "authoritarianism" or "totalitarianism" can get through the propaganda without grappling with the double standards inherent to the concept and coming out the other side significantly different
yeah that sounds pretty different from the sorts of situations i'm talking about, it makes a lot of sense to be cynical over it though. i think seasoned anarchists, even if they fully mean well, can turn orgs not explicitly laid out like that into something really unpleasant. there's a kind of normative behavior that comes out of consensus based organizing that's very focused on raising basically every single concern you might have and avoiding keeping quiet for the sake of getting along that is pretty essential for consensus to work as intended but can end up pretty obnoxious outside of that context. maybe the only way out is just not going along anymore if enough ppl are tired of it even if it'll likely be unpleasant.
that's def what happened to me, a huge turning point for me was participating in an small group with a very anarchist structure and seeing all the issues that creates, and eventually finding myself in the small group of de facto leaders doing evil unaccountable centralism bc of a combo of social cachet and being one of the few ppl to actually bother showing up to meetings. coming across The Tyranny of Structurelessness was an unpleasant literally me moment. ragging on ML organizing for not being democratic enough made a lot of sense until everyone's silently democratically decided you're responsible for everything or else the whole thing falls apart
Just to defend the vast majority of people who subscribe to anarchism a little, ime huge amount of self proclaimed anarchists don't have particularly strong opinions on methods for organizing or effecting change at scale, mostly because a lot haven't done much organizing. In my experiences with anarchist types they're pretty flexible on the methods part just because it's nice to do anything for a change and doing basic organizing in the maximally anarchist fashion can just get exhausting.
Granted i'm mostly talking abt like new to leftism anarchist by default types but the anarchists who're ideologically committed to the point of opposing all centralization in organizing bc authority are overrepresented online and irl MLs are incredibly unlikely to even have a chance to work with them.
i think being trans probably pushed me towards the left, before i figured that out abt myself i literally couldn't articulate an actual reason for why i felt drawn towards the left instead of being a typical shitlib like my class and cultural background would dictate.
Going full 
def isn't the default tho, so i attribute the rest to getting an i think above average level of education on american slavery and british colonialism (really a bizarre amount of british history for an american teenager, basically covered the transition from feudalism to capitalism over like 3 years of highschool) early on and then getting exposed to Indigenous ideas and history taking college electives. All that and having a special interest abt the Vietnam War instilled a really strong hatred and disgust towards the colonial/imperial mindset which is what's pulled me more and more towards being a massive tankie.
I did start out on the more libertarian anarchist type side of the left mostly bc that's what most people around me were, but the more i read and talked abt things like decolonization and whiteness the answers from that school of thought just weren't satisfying or convincing to me and i really started to distrust the way the (exclusively white) anarchists/libsocs/mainstream leftists around me engaged with what is imo the most important question for the left in this country. Not that every white person is personally culpable and incapable of solidarity but a lot of the engagement from my fellow 
lefties feels way too focused on absolution in a way that icks me out and is probably related to a bigger overcorrection away from the whole personal responsibility thing.
went off on a tangent kinda but TL;DR trans woman indoctrinated into being a self hating anti-white racist by woke history classes, becomes a turbo tankie 
who no longer believes in freedom bc whitey won't voluntarily do what must be done without reeducation
pro-Hamas domestic woke terrorists are secretly building an elaborate hose network to facilitate a full scale invasion of our beautiful suburban lawns