I think this is the practical view, where we are talking the art of the possible AKA politics. We are stuck with the deranged bully, his adoring and fact-immune base, and his indelible impression that he is strong, authoritative, and gets things done, no matter what a monstrous fraud that all is. Whatever Trump's cognitive decline, it has not alas affected his grifter powers. Calling for Joe to step down seems like a viable course precisely because Biden is not Trump, but rather a decent and reasonable man.
Trump lied his head off. It got less coverage because news outlets cover news, and Trump's bullying and lies are "Dog bites Man." Or "Water is Wet."
I agree that Democrats stink at the whole party machine thing, where wise veterans gather in the proverbial smoke filled room and hash out the nuts and bolts of candidate selection. It's a shame given all the potential great pairings out there....Gretchen Whitmer and Ralph Warnock, Newsom and Gina Raimondo, Harris and Sherrod Brown, Andy Beshear and Cory Booker...hell, you could throw the top dozen into a basket and hold a random drawing and get a duo that would reenergize the Dems and leaning Independents.