Being a CEO of a company has some disadvantages one of them being restrictions on selling shares (to avoid insider trading). He cant suddenly bailout with his share if he wants. Acc to rules he would have to declare his sale in advance . If that happens then the share price will fall and reduce his net worth as a result.
Teslas valuations are absolutely mindboggling but if you listen to the general discourse amongst Americans, for them Tesla is a company of the future that will dominate critical sectors like Space (SPaceX), Cars, Clean Energy etc Hence the massive bets on it.