It is wrong to think it has nothing to do with intelligence, especially repeated success.
And do you think an 80 IQ founder == 120 IQ founder all else being equal?
Musk and Bezos seem to have come to roughly similar outcomes, so evidence suggests yes.
Founders aren't the ones with the money. They're making it for someone else and then being paid for that.
In any case, it's what happens on average that matters, not minuscule exceptions. Money makes money.
I don't think its possible, or fair, to reduce success to a single digestible dimension.
And somone had to come out the winner in a stochastic Market. It just halpened to be Musk. No competence requirer, at all.