Economic stability alone is not enough for a currency to be an important store of wealth. China doesn’t have a free floating exchange, it has very strict capital controls and lacks political and legal predictability. You need very specific institutional foundations to have a currency like the USD, which the Chinese political system rejects. The US has an independent legal system. If you have a dispute with the US government you can take it to an independent court. In China, you have no way to sue the CPP. China is a single party socialist republic with all the political authority concentrated at the top, so one high impact event like the sudden dead of Xi Jinping could send its economy into fallout because of political uncertainty. In the US the system is explicitly designed to absorb this type of shocks. So for these and many other reasons the Yuan under the current Chinese political system will never be a serious contender to the USD as global currency, it’s just way too much institutional risk for foreign investors. It’s also very unlikely the CPP will ever pick a Yuan rivaling the USD vs political control over their domestic policy. They can’t have both.