Bill Nelson and Andrew Gillium lost by less than half a point. The polls weren't actually that far off. Those races were so close that a minor shift either way would change the outcome. Nelson was up 2.6 per RCP and lost by 0.2, less than a 3 point shift. There was also Wisconsin in which RCP had Baldwin up 10.6 and she won by 10.8, if there was a 2.5 shift in that race, it wouldn't have mattered. Things have changed since 2018 and we have actual election where Democrats are overperforming.