I do think a Biden presidency will be better than 4 more years of Trump would have been. That's not even a question.
I don't think both are corrupt to the core, but both could stand to fracture. The GOP needs it more than the Dems do, but the Dems could stand to break up as well. RCV will allow that to happen. Not overnight, but it would allow them to fracture and/or give existing 3rd parties a chance to really challenge them. Either way, the duopoly is severely weakened and the ossification we've seen is allowed to break up and evolve again.