I agree with most of this, and Biden wouldn't be my choice.
But the bolded simply isn't correct, and is in fact arguably the best reason to nominate Biden. The people and places that swung to Trump in 2016 LOVE Biden. He's basically one of them- an old white Catholic guy from Scranton, PA who grew up blue collar, played football and went to state school, and speaks plainly and sometimes a little politically incorrect. He was the VP of a campaign they supported twice and of an administration that saved the auto industry as the GOP railed against the bailout.
I understand it makes no sense to people like you and I, who see him as old and lacking new ideas or a broader appeal and would consider his nomination something akin to "running it back with the same faces and hoping to coast back to power," as you put it. But that's not how the voters in the Great Lakes see it. It may not seem rational, but neither does the appeal of a billionaire real estate heir from Manhattan who has spent his entire life accumulating wealth by defrauding the working class. We've already seen the peril of minimizing their perspective in favor of ours.
That doesn't necessarily make him the best choice. There's lots of other variables- drumming up enthusiasm from young voters and minorities, his #metoo issues, the Iraq war vote, and obviously the small matter of how he'd actually govern. But there are huge factors in his favor, and we should acknowledge them and not kid ourselves.