He's only the "richest" man in the world because of the inflated valuations of his companies. At some point the market looks like a dog chasing its own tail:
Q: Why is this stock so valuable? A: Duh, because Musk is worth a kajillion dollars and everything he touches is gold!
Q: Why is Musk worth a kajillion dollars? A: Because he holds so many shares of extremely valuable companies, silly!
Q: Why is this stock so valuable? A: Duh, because Musk is worth a kajillion dollars and everything he touches is gold!
Q: Why is Musk worth a kajillion dollars? A: Because he holds so many shares of extremely valuable companies, silly!