Have we considered the possibility that 4 months is an eternity now (quick, tell me from memory what everyone was arguing about in late February!) and if Biden looks good in a future debate the only people who will remember Thursday are people who were never, ever going to vote for him anyway.
I know we all live in an ideological social media bubble but I promise you video clips of Biden looking ancient and sounding like he chose the wrong Grail have been circulating in abundance for a very long while now! They don't have special power if they are from The Official Debate!