On top of what you just mentioned, rather than Trump surrounding himself with incompetent toadies and yes-men, I think a lot of smarter, more powerful, and more dangerous people have taken the last 4 years to worm their way into his ranks.
He’s established himself as a useful idiot. During his first 4 years we saw the idiot part glaringly. It was scary and embarrassing, but we scraped by and experienced a few years of relatively boring politics. My big worry is that we’ll see the useful part exploited much more effectively this time around.
“The economy” is just a wildcard character for whichever of 6000 different metrics a low information voter wants to use to justify voting R.
Gas prices, inflation, wage growth, GDP, corporate profits, the Dow Jones… one of them is sure to be better when the R was president and another one is sure to be worse when a D is president.