Your mistaken bitcoin is already a global currency considering that most of the world population is using and has knowledge about it, some even invested in it. And not a single individual can control the price of it cause it's a decentralized currency no one owns it. Not even the devs because without it's users they have no job right now.
I dont think so that there can be any such reason which can stop bitcoin from being a global currency. In fact, bitcoin is the global currency as the people living in all the corners of this world are busy in investing of their money into any of the crypto coin and that they are doing it without any worries. There is no such restriction which can stop you from investing in bitcoin or from becoming the owner of the bitcoin.