Your post seems very one-sided and incomplete.
It was, I must say, the worst debate I've ever seen - a fiasco on both sides.
Trump was horrifying, and it's hard to understand why anyone would vote for him. He perpetually evaded the questions, spoke grandiosely but vaguely, and he told lie after lie - possibly getting bolder as he saw that the moderators weren't going to fact-check him.
Biden's problem is partly one of personality. He comes from a civilized background and is still unused to that kind of vicious, lying attack. That's how Trump achieved prominence in the first place - in 2016, his opponents in the same party had no idea how to deal with the lies and personal attacks, and one by one they all fell by the wayside.
Personally, I suspect there was another basic problem. You may be aware that when he was young, Biden stuttered, and he did a magnificent job of overcoming that. I have a feeling that Biden was foolishly talking quickly to get in as much a response as possible, and he started tripping over his words, which made him sound as though he was losing his grip.
But, yes, it's frightening. I think his biggest problem - I mean, the biggest problem with a solution - is Kamala Harris. He should choose a different V.P.
In any case, what people may not realize is that Biden, even if less in command, has a good agenda and hires good, competent people, while Trump has what's basically a vicious, self-serving, anti-democratic agenda, and will hire criminal cronies.