bitcoin has already been a global currency since it was first created. Satoshi waant people to use this coin as a primary school on the global and this coin is a symbol of the crypto currency revolution
Perhaps still not as much globally as you think. Because the fact is that only a certain number of people use crypto currency and there is no talk of mass use of speech.
although the number of bitcoin users are few but i think they are present everywhere, i do not think that there will be a single country where the users of bitcoin will not available. and in this sense we can say that bitcoin is is universal currency and we are hopeful that the users of bitcoin will be increasing more and more.
Bitcoin is already a global currency in online space, but if it's applied to real currency obviously can not yet because it will damage the dominance of fiat in many countries. I think bitcoin will be a kind of stake in market trading, and not bound as a real currency. They are just as liquid as gold and other asset products.
You have a wrong observation about bitcoin as if bitcoin is being applied in the real world then it will also be a normal currency when all of the people of the world will adopt it then the liquidity of bitcoin will not be like that of gold as then it will act like dollar. It will have a fixed stable price and people will like to use it for their international dealings.