BTC being a global currency in cryptocurrency is real, but not for the world. because what I see if it becomes the world's global currency it will be difficult because now not all countries approve of bitcoin and recognize bitcoin as one of the global currencies
Although there are many problems and difficulties in travelling Bitcoin. But this is satisfied that its popularity acceptance & adopting is increasing day by day. The legal process is also continuing towards betterment. It has crossed many limits of borders and this process continues successfully.
If we look into fifty years befoe, then no one can say that the invention of the computer and then internet development will make this world a Global village. But today you can see it has happened. So there is also the possibity that crypto may be a Global currency in future.