This reminds me of "I will Fear No Evil" by Robert A Heinlein. The billionaire with a brain transplant into his secretary remarked something along the lines of "Once you get rich enough you can't help making more money than you can spend."

It seems from a distance, Elon tried to spend all his money on a Mars exploration, solar power, and to force automakers to start building electric cars. But then he just made more money. I can only imagine how rich he'll be after Starlink gets going in earnest.