Many rich people still earn a paycheck. YOu can be on payroll making 500k and have a stock portfolio worth 10mill, this is common for boomers who started investing in the 70s and 80s. A portfolio of that size will easily throw off 500k in dividends a year.
My point is that a large paycheck does not mean you are not paid wages. I get your point though, billionaires probably are not taking a salary.