I think that if there is one thing the US' political system shows is that you're still supporting great evil, just at a strategical level rather than a more inmediate tactical one: if all a politician needs to gain power is to be perceived as less evil that the other one they have way more room for evilness (pretty much all the way up to were the other one sits in that scale) than they would if they had to convince voters by the quality of their own actions.

As we're seing, over multiple electoral cycles the result of this is that, as one side pulls further and further into "complete total nutter" levels, the other side also becomes more and more so, just not quite as much: one side is still less evil that the other but both are more evil than their predecessors something which would never happenned if people refuse to votde for any evil.

This is how for example we ended up with Reaganism adopted by both parties in the US (hence they both only really represent the upper classes when it comes to things like Quality of Life and Economics) and the situation now with Biden supporting Genocide and unwilling to roll that support back (which, if you think about it, would be the only way he could get a significant fraction of votes in a system were people voted for good rather than accept evil "as long as its lesser") - with people voting like that politicians don't need to be good, much less better than before, they only need to a tiny bit better than "the other guy", so they keep getting worse (hence how Democrats are now active supporters of Genocide)

By voting evil with merelly a moving reference (the greater evil) as constraint, you're enabling evil to grow, and that's exactly what you've gotten in the US over the last 4 decades were Quality Of Live has gotten worse and worse for the majority, Social Mobility has gone down a cliff (and is now worse than most of Europe, when it used to be better) culminating with the current "choice" between 2 candidates who both support a nation led by openly racist Fascists who are active commiting a Genocide.

Choose evil, Get evil - even if you salve your conscience by saying "yeah, but it could've been worse" (which, funilly enough, is a common cope of the submissive and the mediocre).

Forgive me the crudness but from were I'm standing it looks a lot like Biden is treating a significant fraction of the electorate as his bitches: cowed into keeping on coming back no matter what he does "because it could be worse", with even some bitches activelly convincing the other bitches not to leave.

Yall sounds like protection racket. "Give us your vote or you'll get killed"

I think blank votes are ignored because there are so few of them.

If an election is getting 10 or 20% blank votes, that's hard to ignore because it means a huge fraction of actually engaged and active voters - who could've just as easilly put a cross somewhere - aren't being served.

Amongst other things it tells existing parties that "my vote is here for the taking".