It's not a good tool if one party is likely, but not guaranteed, to win without your vote, but is much worse than the other. You should only spoil your ballot if your constituency is has a large enough majority that your vote won't matter at all, or none of the parties are less bad than the others.

If you're voting on the single issue of Palestine in the US presidential elections (not the primaries), then no state has a large enough majority to justify as spoiled ballots, and one party wants to support a genocide while the other wants to discourage it (even if they're doing a crap job of it), so there is a least bad option to vote for.

Except we have an actual self proclaimed dictator, trying to gain power. These fucking "progressives" are helping him.

As someone with a modicum of common sense, it boggles my mind that these spoiled children think helping Trump seize power is a good idea for anyone including themselves.

I don't understand the motivation to spoil your vote. First past the post is the shittiest voting system but the rational response is to vote tactically instead, perhaps reduce the majority of your disliked incumbent. Even if you can't overturn a majority, MPs on smaller majorities may be less arrogant, and less likely to vote for unpopular policies. But sometimes you do overturn a majority. It will happen lots in this/next year's election.

I don't think any politician gives a shit about the numbers of spoiled ballots, they literally don't look even once at those numbers.

I live in maryland so my ballot doesn't matter much regardless for the presidential election. If Biden loses maryland he loses. And I won't be voting for him. The worst thing missing my vote will do for him is reducing his popular vote. Since that's mostly a talking point, good.