What if Biden has been faking his mental befuddlement and physical frailty as a way to avoid prison for some combination of (a) mishandling secret documents, (b) taking bribes from and acting unregistered on behalf of foreign and sometimes hostile governments, and (c) failure to enforce duly enacted federal immigration laws.
In this scenario, he actually plans to not run in 2024, but to withdraw his candidacy at the last possible moment before the convention, immediately after pardoning both his son Hunter and himself. I'm guessing he'd ask his delegates to switch their allegiance to Gavin Newsom, since CA seems to be the incubator and poster child for Democrat policies. Newsom could even be in on the scheme, couldn't he?
What probability would I put on this theory being prophetic? Maybe a 10-15% chance.