Bitcoin can already be traded is all countries given a person has access to a device and the internet. It is some of the peripheral activities around it, like fiat onramps, where there may be more restrictions in some countries versus others.
It might be possible that majority are able to access Bitcoin as long as there's an Internet connection. But, I think we cannot guarantee that Bitcoin is accessible globally where some of the people are in the rare and far location from civilization. I guess the world will become 100% connected to Bitcoin more years from now.
That is only a small part that you are pointing mate and those who cannot access bitcoin or internet are surely the people that cannot afford using crypto also.
Sooner or later bitcoin will become global trading currency. I have a strong believe that one day bitcoin will takeover all other means of trade like gold and Dollar.
Note: You can disagree with me by proper arguments.
absolutely , bitcoin or the whole cryptocurrency will soon be the major currency or the currency of the world , and will end the reign of Fiat and Gold.