They can be competitive in local elections that the larger ones dont put as much effort into,

That’s my point, though. The two biggest third parties in this country aren’t competitive in local elections, because they put even less effort in local elections as the two major parties do. They make a performative shot at the presidency every four years, and that’s about fucking it. The Libertarians are slightly better (god, what a sentence to gag on) on this than the Greens, but not by much.