none of those candidates will get enough popular votes to win a state’s electoral votes and 2 out of 3 aren’t on enough ballots to total 270 votes. the only message a person who is on the left side of politics teaches the democratic party is that your vote isn’t worth pursuing since you aren’t going to vote for a democrat anyway. instead they will pursue the votes they have the possibility to get. often those people are much more centrist or right wing. you’re taking yourself out of any potential influential position of influence.
this is a binary choice. the winner will either be trump or biden. any vote not for biden is an indirect vote for trump because it’s not going towards the only other viable candidate. this is how our system works and it’s far too late to change it for this year.