Because it’s an election with consequences, not an online fandom.

Not to most of these people pushing third-parties.

All elections have consequences. I know that Americans like to be dramatic (especially on Lemmy, Reddit is far more tame in this regard), but voting for someone that wants to promote policies that you support is how those policies are promoted.

I say this time and time again on here, but America isn't special. Many countries have two main parties, but while third parties don't always see power, they maintain Influence everywhere. Hell, you can argue that the Tea Party, Brexit, Irish Unification, MAGA, Immigration reform in Germany, all of this is due to influence outside of the main parties.