He assembled a team and they learned to use him in the roles he fits best - getting attention and investment money. He is not a brilliant aerospace engineer.

I believe he’s better observed in Twitter, which is a company that didn’t develop an immune system to deal with him.

SpaceX and Tesla both enjoyed most success despite Musk's continual rank incompetence by isolating him as the figurehead money guy while puffing his ego letting him cosplay a rocket scientist/tech expert for the press. At both companies he's got handlers to limit and manage the damage he causes. At Twitter he had no handlers and his rank incompetence is on full display, as it was in the PayPal days when he was rightly fired for incompetence.