to pressure biden into stop supporting genocide if he wants to win -
No, the point is to threaten to reject electoralism and show the rest of the US population how farcical it is, and to show that there is a large number of people not buying into this syatem or its propaganda. If you don't vote for president this election and then vote again in the next one, they were right and you're really a pathetic cowed-and-beaten loyal subject.
Does that really count as voting for Starmer though? I get how voting for your MP counts as voting for the party leader, but your local councilors or whatever don't decide the PM.
Brandon is going to promise a lot of things, but none of it should be taken seriously. He is a shameless liar and will not uphold any campaign promises if he is elected in 2024.