It is obvious to anyone willing to make an impartial evaluation that dementia Joe is on that long sad slide into oblivion. That's a tragedy for him and his family. Yes that lack of mental capacity disqualifies him from becoming President.
The real questions right now are who is pushing him forward anyway, and who is (and would be) providing his answers? Who would be scripting his responses to questions? Who would be providing his notes and talking points for meetings with heads of state? Who would be writing the agenda for staff meetings and giving the cabinet their marching orders?
Someone or several someones out there want(s) to play President. Dementia Joe & the Ho are just the the figureheads.
Tragedy for his family?
Hardly. His wife wants to be First Lady more than anything. She is what pushed him into this. She is what keeps him in it.