They key here is that 2016 saw a couple of third party candidates pull about 4% of the vote away from the main candidates. So in 2020 where that wasn't really a factor, Trump's vote % went from 46.09% to 46.86%, while the Democratic candidate went from 48.18% to 51.31%, as the third party balloting fell off to just over 1% of votes cast. So almost all of that third part vote which left third parties went to Biden. It is easy to see with all of the really small state margins of victory in 2016, how very small voting movements like this pushed the election to Biden.