He won't go away. He's too narcissistic to go away.
My concern with him is not him having a 2nd term, is forcing his way into a 3rd, 4th, 5th, etc term. People like him never let go, and there's no low that's too low. That's what fascists and dictators are made of.
Now, he's embodied the polarization between parties, and that makes him less likeable to independents, which ultimately win elections. That's the calculation here about him being candidate vs, say, a similar newcomer in DeathSantis, who is a less known quan y (and in this day and age is a plus).
He can absolutely win, I have no doubt about it. Dems keep rolling out terrible candidates as well, and I think running Joe for a second term is a mistake (I thought he was a mistake for the last election as well, but credit to him, he did win).