Yes, It can be expected that cryptocurrency will be a Global currency in the future.
The BTC will be the father coin and there will be a lot of sub coins.
Cryptocurrency is a unique kind of currency that has great potential.
It has an attraction for all ages of life. It has a great opportunity for those who want to do something and desire to step forward.
Moreover, It has equal chances for poor or rich for development .
This currency has brought a revolutionary change in the world of business and trade.
It promotes a positive activity also.
It's impossible to happen. The central organization won't let the cryptocurrencies dominate the world. The government is always against something it cannot control nor manipulate. Hence, most government of different countries don't see crypto the way we do. They either see it as a threat or nothing at all. Despite all of the positive feedbacks about crypto and all of its advantages, there are just government officials and people, in general, that are close-minded. They are not open with the idea of having it or legalizing it.
In addition, each countries have the local currency of their own which they plan to boost. Which clearly indicates that the adoption of crypto into something big, particularly being a global currency is just another dream. Since not all countries are open to it and only a few recognize it.