Polls are crap
It’s a little bit notable how they change over time, but mostly it is just a bunch of poor methodology noise
But, I do feel it’s relevant to point out that even in polling land Biden has been gaining for the last few weeks and it’s notable which media outlets are pretending it is the opposite of that (like severely the opposite) and to wonder why that is
Yup, only one thing affects his chances of winning, and that’s voters in swing states. If all the ones that don’t like him vote for Biden, he’ll lose easily. If they don’t, he has a good chance to win.