"But he's better than Trump!" is not the point. Yes, he's infinitely better than Trump. He is also manifestly not up to the demands of this moment. You can scream about Trump, the media, the moderators, the format, panicky Democrats, whatever. That is not going to make any of this go away.
The most maddening part: Biden could have presented himself, from the beginning, as a wise man overseeing a brilliant team, and we would be voting to reelect that team. Instead, he has made his Cabinet anonymous. There's just this one ancient guy convinced that only he can save the world from Trump.
If it's not Biden it's Kamala. If I'm reading you right and the point is that Biden isn't great and something needs to be done, you need to be explicitly making the case that Kamala will be better. Thus far I haven't seen any polling that's backed that up.