Democrats might suck as far their desire, willingness, and ability to implement actual leftist reforms, but they are not as purposefully cruel. Suffering is real, more suffering is worse than less suffering, and one party is openly sadist.

Cop City is a complete counter to this argument. It's in Atlanta, a Democrat stronghold. It's obvious Cop City is a response to the George Floyd uprising, which the Democrats alongside the Republicans suppressed through counterinsurgency. Your fundamental error is believing the two parties aren't part of a domestic counterinsurgency apparatus. An effective COIN apparatus employs the carrot and the stick. Of course the carrot is less immediately painful than the stick. That's the function of the carrot. But do you think the good cop is somehow better than the bad cop, especially when they're working together as a team?

Also, one party will make your goal of making the world a better place (which I assume is your ultimate goal) much more risky than the other. Why would you make your goal more difficult to achieve out of spite?

This is not really substantiated. You could easily make the argument that the Republicans are so openly reprehensible that people are far more likely to rise up like we saw with how the George Floyd uprising was partially fueled by Trump being an open fascist. Both this argument and your argument make the error that the Republicans and Democrats aren't working together. Just because they have different roles doesn't mean they aren't part of the same team.

I realize that the Democrats are not going to bring about communist utopia, but as a trans person, one party winning power makes me scared of going about daily life, makes me wonder if my medication will be banned, whether I'll be prohibited from public areas because of my identity -- the other doesn't. But I guess you don't care about any of that.

Democrats don't enshrine anything into law, meaning whatever fascist bullshit the Republicans come up with will be put up without a fight. Plus, federalism means those bullshit laws get passed anyways regardless who's president. We saw this with Roe vs Wade where Democrats didn't do shit after the Supreme Court ruled in favor of reproductive rights. They don't do shit when they're in power, and they aren't an opposition party when not in power.

If you think voting Democrat will make your revolution less likely or take longer, and you are willing to let harm happen to make it happen faster than you are an accelerationist - a morally tenuous position at best.

Voting Democrat is at best a stalling tactic until Republicans drive the car off the cliff. If it's in the context of you and your loved ones fleeing the US to a more progressive country, then yes, voting Democrat makes perfect sense since you would be out of the car when the car goes overboard. But if you have no real plans of immigrating to another country, voting Democrat means nothing since the car is going overboard anyways. Or it would be going overboard unless we wrestle control of the car from both the Democrats and Republicans.