It's true that every country can print as much fiat money as they want. It is obviously not true that this will make everyone rich because money is not wealth. Money is just an accounting system. It is useful to have a money supply that tracks actual wealth because it is useful to have stable prices. It makes planning easier. Fiat money is useful because it allows inflation/defaltion to be controlled by policy rather than the whims of fate. But it's still up to us to choose the right policy.