The way Bloomberg Terminal (and many others) calculate net worth is always wildly optimistic as it doesn't take into account market depth.
On any given day, only a fraction of the total market capitalization of stock is traded, and basic laws of supply and demand dictate the price of that stock.
Then Bloomberg takes that stock price, multiplies it by the number of shares a particular person has, then claims that is their net worth.
But for big whales who own more shares than the daily, weekly or monthly market volumes, if they were to actually sell their shares, then they would massively suppress the price as they would increase the supply, and there would likely be no one in the market to take up demand at the current price.
Bankman-Fried was never going to be able to sell all his units of FTX for $16B. Even now, he can't actually sell all his units of FTX for $991 million. These numbers are almost completely fictional, with only the lightest shoestring tie to reality.