Most US Conservatives think that the 2020 election was rigged.

So why bother standing in the next one? It doesn't make any sense, if you genuinely think that the system will be set against you.

Also, the Democrats rigged it extremely badly because they didn't give themselves a super-majority.

It's a case of people choosing to believe what they want. If all politicians are liars, then pick the lie you like the best. suspend disbelief, like you would watching a movie.