I think you're giving Biden too much credit. He really was not in charge. The DNC and his staff/family all knew it.

They were shielding him from the bulk of his duties, and someone else was running policy. Who knows who?

Speaker Johnson recently talked about how it took the White House weeks to let him meet with the President. When he finally got him alone, he asked Biden about why he signed an EO ending natgas exports to europe. Biden had no idea what he was talking about. That was in October 2023.

We're never going to find out who was actually in charge. For people worried about Democracy, the blue tribe seems very uncurious about this issue.