United states by far the most country having millionaires. Not a coincidence I believe. It has the Federal Reserve that can print money and increase the money supply as much as the system wants. USD is the world reserve currency, not because all major countries like it or not, or see it stable or not, but because forcing this from the US side on most world countries.
Will this ever change. Probably yes, and so soon. Technology did change everything around us. Still monetary systems and world financial order to be changed.