Elon Musk has certainly been made very rich from ideas alone.
No... teams of people had to execute on those ideas first, usually with far more valuable ideas of their own, as well as teams of engineers and employees to make them a physical and profitable reality. He didn't simply manifest his ideas from the aether like an arcane sorcerer.
He has delivered on many things, and not delivered on many other ideas. It’s just that the things he didn’t deliver ( the vision ) helped him sell stocks as well as cars, via fame.