I honestly feel bad for people like you who see money as the only measure of someone's intelligence or worth. Donald Trump has multiplied his coffers by being elected, so I guess he has a brilliant mind too. Take two steps back and you'd realize there's actually very little smarts behind an incredibly rich person becoming richer.
Floyd got to where he is through a lot of hard work and talent, but he isn't smart. He might have hired smart people to manage his money for him, but the man himself is one of the worst living examples of a sports celebrity. A vile person in every way.
Ninja Scooter pretty much addressed this post for me.
All I'll add to that is this: Floyd had an incredible career after several decades of boxing. He made very smart choices, became his own promoter, cultivated his own image, and then walked away with his health in tact and several hundred million invested for his children's futures. The man won at life. So many good boxers - great boxers, even - before him, ended with nothing, not even their health, and some of them millions in debt.
Floyd is young, rich, successful and he has his health. That doesn't just happen. It doesn't just happens to be by luck. It's the result of a lifetime of smart decisions.
Granted, this doesn't change the fact he has said and done awful things, of course, but like I said, regardless of what you think of him, evidently, the motherfucker is pretty smart.