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
If I am remembering correctly then fivethirtyeight gave him a ~33% chance of winning, which was absolutely within the realm of possibility
I think it may have been around 20%, but 1 out of 5 is still reasonable.