Absolutely no one would have ever suggested that electric cars and rockets were the way to become rich. Instead back when he invested in and or started these companies people would have told him it was a quick way to become poor. I really dont think he was ever seeking becoming the richest person in the world.

He didn't start Tesla and SpaceX was possible because of NASA's program to create a market for a private space industry. Both are heavily government subsidized enterprises. If I was a betting man, building government subsidized companies does not seem like a way to become poor.