Because the mentally incapacitated guy won’t leave.
The plan was for Joe to only serve one term (he said so himself) while they found another Dem who could appear to be palatable to the masses. But they don’t have anyone who isn’t a Communist and Joe won’t leave because it takes a lot of money to keep his family running.
At this point if Biden leaves office, he and his family may actually be subject to a real investigation. He can't afford that.
Better that he literally dies in office and thus can't be investigated. Better that then he becomes a public citizen again and a pissed off president decides to force investigation.
