Certainly, very few people possess the brilliance of Jobs or Musk. But, I doubt Twitter and Square demand the same sort of brilliance from a leader as Tesla, Space X and Apple do/did. A quality that Musk and Jobs have that Dorsey might, is their work ethic, which is far more common than true brilliance, and probably more relevant to the challenge of being the CEO of multiple companies.

Although, maybe being in charge of multiple companies diluted the efforts of Jobs and Musk, but it was made up for by their brilliance and leadership skills. An hour of effort from Dorsey might be equal in gains to five minutes of effort by Musk. If that's the case, then maybe you're right.