Why are Joe Biden's rallies so empty? is it cause his supporters are staying inside because of Covid or are they just not interested at all?

He's not holding big rallies because of covid.  So crowds can't go see him even if they wanted to.   The events which he's held are mainly small scale events with a few members of the public there (as well as reporters of course). 

They’re interested in voting and that’s what counts.

They are the silent majority.

Because they’re not idiots like the trump supporters. Their head idiot got covid and yet, there they are trying to get infected.