How much of that is actual liquid assets though.
A big issue with a lot of these conversation is that we take the current market value of their assets and then equate it to cash on hand. All the billionaires have most of the wealth in non-liquid assets and if they were forced to liquidate all their assets to cash could they even do it for the same current market value of those assets?
Musk owns about 411 million share of Tesla stock as of Feb this year. Current market price is $147. What happens to that share value if he starts liquidating those shares and how fast could he liquidate them before one of the other share holders, the NYSE, SEC or any number of others stake holders files an injunction against him to stop him from selling more stock, all the while the value of the stock crashes.
If anyone doesn't believe me look at the timeline that lead up to the collapse of FTX. One of the factors was the CEO of Binance, Changpeng Zhao, announcing that he was going to liquidate his position in FTX. Just the announcement caused the market to go into chaos even though it would take months to complete the trade. Binance and FTX were small players compared to Elon Musk.
The man on his own could collapse multiple countries stock exchanges and banking systems if he tried to liquidate his Tesla stock. That does raise the specter of the question of "Why should anyone have that much control over the international markets/banking system?".
The only answer is that governments and politicians allow him to exist for tangible and non-tangible reasons, taxation being one of them.
https://www.cnn.com/2022/02/10/inves...ill/index.html
Elon paid 11 billion in taxes in 2022 due to his sale of tesla stock to finance his Twitter purchase. This was a unique situation though and most years he only pays about 60-70k in taxes because he restricts his income to meet his tax deductions. Income however is not wealth and the USA does not have and most likely will never have a wealth tax so we have to limit tax extraction to sales and income taxes. Even that low amount is multiples of how much an average household pays in taxes per year (about 17k for a family of four if you include all taxes).
Its up for debate if what Musk or any billionaire brings into the economies in which they operate in if it makes up for the destabilizing influence of their ownership stake in that economy.