I remember. The polls were accurate. The pundits were not. People were shocked because they didn't want to believe that there are really that many loathsome morons around, not because they looked at what polls said.
Here are the main polls for that race on the eve of the election. What they actually said was that the race was close to a tossup, with Clinton perhaps very slightly favoured to win.
Here and here are favourability ratings. As you can see, Trump's are substantially less negative.
The polling wasn't off in 2016, it was actually super accurate and missed the result by only one point.
Trump isn't popular, but he doesn't need to be, he just needs to be less unpopular than Biden, and right now polling is suggesting that he is exactly that.