Genius was hyperbolic. That is, I wanted some examples of Biden's supposed smart moves and such along with some of Trump's obviously stupid ones. If Trump is truly as stupid as you claim it should be a snap to give say 3 to 5 examples of that.
I can easily do that with Biden...
He plagiarized in law school and got caught, then did it again in his first presidential campaign and got caught. Someone smart would have learned the first time...
He tells "fish stories" (tall tales) like "I drove a truck (18 wheeler)..." or claiming one home he owned burned down (minor kitchen fire), or how he tries to spin himself as blue-collar worker when he's spent nearly his entire adult life in Dirty City as a politician... Telling obvious lies like that comes back to bite you in the ass. He hasn't stopped doing it even though it's clear it's not doing him any favors.
He says dangerous and insane things, like saying all you need for home defense is a shotgun and you should just fire it couple of times in the air to scare off a would be intruder...
Most recently, he's bought into Modern Monetary Theory, a quack radical Leftist economic theory de jure and is wrecking the US economy using it.
https://www.investopedia.com/modern-monetary-theory-mmt-4588060
He insults voters to their face when they question him or ask him something uncomfortable. How smart is it to piss off the very people you need to keep yourself in office?
Even the most ardent Democrat supporters call him out for his stupid statements and lies, like the WaPo. I'm not even tossing in times where he said one thing then did another. Many politicians do that, hell, probably all of them. Biden on the other hand does and says utterly stupid things then doubles down on them.