I believe China's cryptocurrency ban is more about fighting capital flight than scammers. There are restrictions in China on everything from foreign exchange, overseas investments, domestic property, and cross-border payments. They have two separate currencies in part to prevent money from leaving the country.

That said, China is one of the most authoritarian countries in the world. It has some of the most effective controls in place around media, speech, technology, and capital of any country. I'm not sure whether that model could be easily copied, and whether it should be copied is maybe a different conversation altogether.