You're still equating qualities that do not evaluate Trump's ability to govern but to campaign.
There is proof of Trump's blatant idiocy. Some have chosen to ignore it. Though, he may have some experience now... meaning 2020 Trump is definitely an improvement over 2016 Trump, that doesn't mean he's the best candidate to be President. Unfortunately, Trump isn't running against his former self.
Right now, his lack of experience and his ignorance in how our government actually works will be evaluated, hopefully more seriously, by the general public. There is no boogeyman candidate this time. Biden and Sanders are a far cry from Clinton. Though, I'm sure calling one the "most corrupt" and the other a "communist" will fare will in some circles, the people still voted Clinton over Trump in 2016. Trump may win the electoral college again. I sincerely doubt he will win the popular vote. Not because people don't like him, but because most people can see he's a conman.
Constantly having hissy fits on live television and social media, willingness to close the government down when he doesn't get his way, and his rotating cabinet of the people who are "really doing all the work" show that the executive branch from 2016 onward is more a formality rather than a functioning branch of government.
That isn't good enough.
Of course, some people know he's a conman and are his strongest supporters. They think him "shaking things up" is good for the people because destabilizing the government is good for the people. It's not.