Given your edit I feel compelled to point out that two things are true simultaneously:
Direct action is effective and necessary
but also
Direct action is not mutually exclusive with voting in any way.
Voting takes a couple of hours per year (at most) and is a tremendously effective way of keeping fascists out of power and reducing overall harm while we concurrently pursue direct action and systemic change.
I believe it is our moral obligation each day to do what we (reasonably) can, within the circumstances and powers we're given, to ease suffering in our community and our world. On most days that's direct action. On election days it's spending an hour voting for harm reduction. Participating in our shitty electoral system is not an endorsement of it any more than paying taxes is an endorsement of military funding or having a credit score is an endorsement of Equifax. It's simply the reality of having to live within a system we did not create and have limited control over. Refusing to engage with the realities we live under doesn't make them go away - it just means more people get hurt.
I've ruminated and ruminated and ruminated on all of this and I can't find any compelling philosophical or moral argument for allowing the greater evil to take hold, unless there is an imminent, likely possibility of a more just outcome following soon behind. If there was a groundswell of support in the US for a left revolution then perhaps a fascist victory could be the spark to push us towards structural change. But as it stands a plurality of Americans want (or are fine with) fascism, and they're armed to the teeth. The most likely outcome of fascists winning the election is that fascists take over and keep power, and that will cause unfathomable harm far beyond the disgusting shortfalls of our current administration.
It's a trolley problem, essentially. The trolley is coming down the tracks and all we can do is pull the lever to have less people die. I find that a lot of modern discourse around this in left-leaning spaces essentially comes down to "well I don't like either option" or "there shouldn't be a trolley!" or things like that. You know what? I agree. I don't like either option, and there shouldn't be a trolley. I hope we can take more direct action so there are less trolleys and less people tied to the tracks in the future. But here we are, right now, and the trolley is heading down the tracks, and we cannot stop it. It doesn't matter that there shouldn't be a trolley. It's here. Not pulling the lever doesn't make it go away, it just means that more people get hurt.
So please, by all means, prioritize direct action. Get those trolleys off those tracks. But once we're barrelling down the hill it is our moral obligation to spend an hour pulling the lever in whatever direction necessary to minimize harm.