Many actually don’t, they don’t convert (much) the capital to money, so they avoid capital gain-tax (which tends to have exception for business owner and long term holder), often they use company asset (like an average worker gets a phone, a laptop and sometimes a car, but they get a boat, a jet, and a nice house on the company budget), borrow money against stock, and actually don’t need that much of their actual money (remember that a billion is huge we don’t talk about getting a nice house, and a private jet, but multiple airliner, and a brand-new top notch hospital in the centre of an expensive city, including all worker wage for a while).

This is why so many people support a net worth tax like if you pay less than 2% of your net worth in regular tax, then you get an extra tax to reach these 2%