China has supposedly been trying to make their own system. The big problem with that, as I understand it, is that they have massive currency controls - people a

China has supposedly been trying to make their own system. The big problem with that, as I understand it, is that they have massive currency controls - people and companies outside China aren't generally allowed to buy and hold their internal currency, and people within China aren't generally permitted to take it out the country or exchange it for other currencies, with some exceptions that have been clamped down on heavily in the last few years. That means they're not a terribly attractive option as the big central clearinghouse for international payments compared to US dollars.