Considering Musk isn't the founder of Tesla, that's obviously not true. He is the founder of SpaceX so that's probably true that it wouldn't exist without him.

Walter Isaacson doesn't have the best reputation for covering his subjects objectively to be fair. If your source for what Elon has or hasn't done is Isaacson, you aren't standing on very solid ground.

The bigger picture point though is that you can easily argue that the employees at those companies, and not a single man, are responsible for the success of those companies. We give far too much credit to CEOs.