honestly, the smartest are probably pretty "incapable". Social misfits, invisible, basic human disasters. They just see a lot more than everyone else, but lack the mechanisms to do anything about what they see...or maybe their perspicacity extends to humans and they see that there's no point or that it would take more effort than they are willing or able to expend.
Pretty sure Grigori Perelman is smarter than Musk, and there are doubtless even smarter people than Perelman who are even less able than he is to fit into society.
Decent brainpower+ambition+socially apt > superior amounts of raw brainpower