[dagw]

I can't explain myself why they are never mentioned

They're never mentioned in the headline news because they don't stand a chance of winning. But they're actually discussed quite a bit every presidential election, not in terms of if they'll win or not, but if they'll 'take' enough votes from one party to have an effect on a close election.

The Democrats sometimes accuse the Green Party of spoiling their chances by competing for the same voters. This presidential election there was a fair bit of talk about RFK Jr and his presidential run, with lots of speculation that he might take enough votes from Trump to cause the Democrats to win. Republicans are still convinced that the only reason Bill Clinton won was that Ross Perot, a third party candidate who got 19% of the votes, split the Republican vote.