Based on this video I would say this whole debate, the outcome and the reaction has been pre-planned.
This is right after the debate ended and 45 seconds into the video they immediately start with the anti-Biden sentiment.
They've been gaslighting the public for years now about Biden's mental state so they could have just continued doing the same. I don't think this debate was anything out of the ordinary for Biden so far, so an order must have come from somewhere higher up to these talking heads that they should start stating the obvious.
Looking at Trump, on the other hand, all I see is another establishment politician.
My favorite theory right now is that they need someone to put a hold on the Ukraine war and allow the US and the West some breathing room to regroup and build up their military power for a showdown with Russia and China. The people pulling the strings are certainly aware that in case of full out war between the West and the Rest, the West would lose big time at the moment. They've thrown everything into Ukraine and sanctions against Russia and all it accomplished was the complete depletion of Western military potential. They've also realized that the Russians are no pushovers and that their military doctrine is far more advanced and applicable to peer level conflicts as opposed to Nato's asymmetric warfare doctrine against sandal wearing bedouin with AK-47s.
I'm betting they want to bring in Trump to lead the charge on fixing the situation. He's the perfect face for it as they can act like they don't actually want him to do it and berate his policies in the media, all the while encouraging him to do it. Plus, the economic base is going down the crapper, the immigration is out of control, and they need some right wing polices to fix the situation.