Polymarket has established itself as a joke, shit is only 4 years old as well. Likewise with polls, look at the crosstabs, Atlas for example just released a horrific poll, toss the shit on the pile and move on, it's a toss-up and it will likely remain a toss-up and get over the fact that it's a toss-up, that's a large group of Americans for you.
There has been a 0.8% swing due to "trash polls" which 538 claims isn't a significant, I disagree given how close the polling has been but oh well, I'm not a pollster. Atlas claims Trump is winning 52% women (utter joke) and 30% of African Americans (Lmao). C'mon man, you don't need to be a genius to tell that something has gone seriously wrong with this poll.
But I can't be arsed to look and post about every single poll when they're all basically saying the same thing: Toss-Up. Just throw them on the averaging pile and move on, the election is going to be a close race no matter what, it's useless to fret about such minor changes. You can repeat as many times pollsters got 2020 wrong but they also got many post-Dobbs elections wrong (underestimated Democrats).
It's just as likely that pollsters have corrected for their mistakes made in the past, it's even a possibility they're overestimating Trump in an effort to not underestimate him this time, it's not a certainty that "polls were wrong before so they'll be wrong forever" and as for betting firms, I frankly don't give a shit what betting firms say when they're so easily influenced by rich idiots like Musk.