> You can't live your life outside your country's currency though. It has a built-in demand because you have to pay taxes in it. So you're going to have to buy some of it somewhere.
Yes but then you can shop around for conversion and can keep the majority of your liquidity in a vehicle which is less easily manipulated but just as fungible (I am just arguing about the utility of a global, trans-national currency and not speaking to specifics offered by the Facebook coin specifically).
Currently, if you want to hedge against the Yuan but still want to buy goods in China, you don't have many choices. But if vendors accepted some other currency in addition to Yuan, you can convert to Yuan to settle debts with your government and keep your holdings liquid elsewhere.