Because with a 4% WR one is almost guaranteed to not outlive their income stream anyway. You’d have to engineer a higher WR plus the lifetime guarantee in order to attract sophisticated investors. That would leave little room for advertising, operational expenses, etc.
The MMM crowd would demolish an annuity company, with enhanced longevity due to exercise and less consumption of tobacco, fast food, and sugary beverages. Fortunately for the companies, MMMers generally avoid annuities.