He likely borrowed against his wealth in 24 and 25 rather than make any cash income. In doing so, he would avoid taxes since borrowed money is not income. He will pay interest but that rate is far below his tax rate. That's my understanding of one of the most common ways that the exceptionally wealthy (wealthy rather than high income) avoid being taxed. So as their wealth grows, wether it's stocks or any other investments, a wealthy person can extract money from their wealth via loans against it. They don't need to pay taxes on loans since it is not income. If done correctly, the wealth grows at a rate higher than the interest rate that they borrow at.
Wage earners tend to be taxed a lot more as a percentage of income. It's nearly impossible to avoid income taxes as a wage earner. Like the wage earners who paid the 3.3 billion dollars working for Musk owned companies. The companies may withold the money but the employee pays it. It's withheld from their pay.
As I get older, the "flat tax" makes more and more sense to me when it comes to income tax. It seems like the tax code has become a way to keep the have not's from becoming the have's.