Bitcoin is a world currency from the position used by people on almost every continent in the world. But because the reason you explained it will never be a major currency or official currency in some countries. But from my point of view it is not a goal and should not be the goal of bitcoin. Also the fact that through the available bitcoin internet connection around the world makes it global and gives all Bitcoin the opportunity to increase its security, availability, exchange processes also need to be developed and more.
There is no way that we can deny the worth and the capabilities of the bitcoin and that there is no such reason that we can support this argument that bitcoin cannot become a global currency. I am very much positive that bitcoin will one day become the global currency and that it will then lead the world in a better way and that it will give us an opportunity of having a better living.