The models are only as good as the inputs. The inputs are polls, and polling is restricted to a handful of outlets . Anyone who thinks that the polls aren't being insanely gamed is just naive. There is no clearly defined data that can be used to make these predictions like there was in 2008 or 2012.

Reminder that in 2018, people predicted that Dems would certainly take the Senate and win governorships in Florida, Georgia.