Currently, nothing that any of Elons companies are doing is scaling. I don't care if someone back in 2018 wanted to work at Tesla, because of how well Model 3 was doing. Today, the colossal turd that is the Cybertruck is their flagship product, Model 2 is nowhere to be found, Cybertaxis are dangerous, and Roadster is never happening.

For SpaceX, their launches are just as expensive (if not more expensive) compared to traditional methods, they are just subsidizing it, while burning money on Starship that will never reach Mars.

So again, no smart person will ever work of any of Elons companies today based on your criteria.