Remember the heady days of 2016 when the complaint about the DNC was that it's horrific that a party even *possibly* had the power to override the results of a primary and change the candidate from the winner of the most pledged delegates?
To be fair, every serious commentary I’ve seen on this has noted that it would ultimately have to be Biden’s decision to step aside. There’s no proposed road to replacing him without him making the choice.
I'll admit I'm more responding to the unserious commentary of the "why aren't democrats trying to replace him" or "in a functioning democracy they'd be able to get rid of him" varieties.