So, take this point of view as what it is: a view on the situation from an outsider, I am not American, I am a German communist. While I do probably look more closely at American politics than most likely the average American simply from being interested in politics to a pathological degree, I might not have the full picture of an American who is also as interested in politics.

I think in this particular moment, as much as the Democrats do their best to antagonise you, as much as you are correct that someone like Biden will continue with the same status quo bullshit that created the situation to begin with, as much as he won't be helping the people suffering from (neo)-colonialism in a meaningful way overseas - I don't think that this particular election is the time to vote third party. The chance may come, and best then to do it not as individuals based on your personal conscience, but as an organised group, with concrete messaging communicated. And even in other elections and outside this vote, organising for a third party - while I personally don't have a lot of hope for electoral politics - is certainly better than investing energy into the Democratic party, whose supporters seem to have no problems spewing hatred towards you for not agreeing with their party line and view of reality.

But I think underestimating Trump could be genuinely dangerous. Not because he will "ruin America" or anything like that. Simply, because he will be in a position to dial up repression, potentially leaving you with a situation in 2-4 years, where the party you voted for has to move underground, either having gotten outlawed or further marginalised and infiltrated. The situation looks critical enough to me, that under a Trump presidency, unions and leftist orgs will face open persecution much more than under someone like Biden - who is admittedly bad enough. Persecution up to outright criminalising them, to encouraging right-wing militias to kill their members with a slap on the wrist as a consequence or no legal repercussions at all. Yes, I do think that is unfortinately a realisitic possibility. And at this point, I don't think leftist orgs in the US have the resilience yet to efficiently organise in the underground.

That being said, I won't tell you a vitriolic "you will be at fault" if you choose to vote and organise as you want to. I do also see advantages, like getting visibility for your issues and potentially by reaching certain threshholds getting public funding support and the likes (that exists in the US too, right?). But I'd still advise it in this election - as shitty and cynical as it is - to vote for the old fart that doesn't swing the whip of the state as hard on your back as the one that might outright strangle you with it. Getting a proper communist, grassroots organisation running in the United States is important for the whole world, and I fear it will be impossible, or at least much, much harder under Trump (mostly, again, because there are no proper structures in place to move into illegality and organising underground, from everything I can tell.)