The contrast could not be any sharper. Biden laid out his policies for bringing America forward in the world in the face of incredibly challenging issues. Rather than engage with those issues (or the topics which Chris Wallace attempted to showcase), Trump was his usual nasty self and primarily resorted to name calling. America was left with two choices: a seasoned policy expert on the on hand, and a carnival barker on the other.
Biden made the mistake of preparing for a debate. Trump turned it into a boxing match. By constantly interrupting Biden, Trump prevented Biden from fully articulating his arguments. Sure it was a low blow, and Trump may have had little regard for the truth, but he succeeded in his goal: Trump transformed the debate into a spectacle demonstrating his quickness and prowess, compared to Biden allowing himself to be interrupted and look weak/tired.
It is irrelevant if everything Trump said is wrong. People won't remember what was actually said, but they will remember that Trump had much more energy and Biden had difficulty getting his issues across. There is a saying in law: When you don't have the law, argue the facts. When you don't have the facts, bang on the table and yell. That is what Trump did, and very effectively.
Sobotka at the Docks