No it's not. Money is a positive-feedback loop. No intelligence required.
And do you think an 80 IQ founder == 120 IQ founder all else being equal?
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.
Musk and Bezos seem to have come to roughly similar outcomes, so evidence suggests yes.
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.