I like to tell people like this to read Blackshirts and Reds by Parenti. I forget in what detail atm, but he specifically goes over how Nazi Germany and Fascist Italy co-opted working class energy, while being opposed to working class power in actuality. In contrast with the Soviet Union, which had its issues, but was genuinely by/for the working class.

Like the thing these kind of people are talking about is sort of real?... but it's a rightist thing, it's not something Lenin did or Stalin did or Mao did. There are shades of that happening now in the US, the rightists who claim to be ML or communist, but are also "patriots" (claiming there's nothing wrong with being patriotic for a genocidal settler state developed into a global capitalist empire).

Also, I would say the use of the word "authoritarian" generally betrays how lacking a person's political education has been and how desperately they need some grounding in history+theory from non-imperialist sources. Idk the origin of "authoritarian" as a term, but in practice, it gets used as a propaganda buzzword to contrast, claiming that "democracy for the rich" systems are "freedom" and other stuff is "authoritarian." Meanwhile, the US has the highest incarceration rate in the world. Under what rock the freedom is hiding, I don't know. People get told such spooky ghost story narratives about how "authoritarian" those "non freedom" countries are, while ignoring what's in front of them: the "rights" written on a constitution that is as reliable as you are rich and that's about as far as it goes.