Bitcoin was not created to replace fiat, so you don't need to expect it to be like the national currency. But Bitcoin is still global in its own right because it has the potential to play a global role in money.
It is a currency that can be used by everyone at all times, in any country you find yourself in, so I wonder what could be more global than this in Bitcoin. If you are referring to Bitcoin as a global currency like your fiat currency, then just know it won't work. It is playing a better global role than every other currency.
Good point. Bitcoin aimed to be a global currency not to be a legal tender soon, but to become an alternative currency to fiat where it can be used anywhere and anyway you want, and probably at this moment, bitcoin is not that highly utilized. But I believe we are already heading there.
However, I don't think this kind of issue matter to us because all we want is high privacy and anonymity, and if we start using bitcoin as a global currency, then it will lose the essence of our privacy and anonymity.