The richest man in the world is he who commands the largest economy. Wealth is not cash, wealth is not stocks and shares, wealth is what you command.
If you have people, transportation, residence, entertainment, food at your command you are wealthy.
Mao Tse Tung got a pocket allowance of $300 a month, but had at his disposal the entire resources, including humans of China.
I doubt that the MBS has a budget.
What is the wealth of Saudi Arabia, or the UAE, Kuwait, Qatar, that is the wealth of their Sheiks, Emirs, Kings.