I think you're right on all counts. In 4 years, Kamala Harris may be able to win a presidential election (if Biden chooses not to run again--given how onerous the next 4 years will be, I hope for his sake he doesn't). But none of the other challengers would have overcome Trump's incumbent advantage and the chicanery of his enablers / supporters.

Not only would the Democratic candidate have lost, the Senate would still be Trumpy (not just Republican but off-kilter Trumpy) and probably the House would have shifted fringe Republican.

We dodged a cannonball.