If you're a working stiff making $15/h at the end of your career, you're a fool.
$15/h minimum wage is for students and an in-between for unemployed or when you're retired and want to make some extra cash by sitting at WalMart.
Do note that if you are a billionaire, it would be very foolish to spend much of that money. Most of your money would be tied up in your businesses employing thousands or even millions of people, spending that value and converting it into cash means selling off parts of your business, which means you either devalue it or lose control over it. You may need to fire all your employees and destroy all your assets just so you can give them a one-time payment? Then what? They'll get some fancy TV's before they're all unemployed for the next decade?
Going from rich to pauper is easy, not the other way around.