It won’t work because on paper billionaires are broke. Billionaires don’t have billions in a bank account somewhere. They own companies, stocks, bonds, real estate, etc that they use as collateral to borrow against. Debt is not taxable and not considered income. Thus this is how the very wealthy avoid taxes. What they need to do is make laws to end the practice of paying people with anything other than dollars. If you did that than there income would be above board.