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.
To be global currency not only can be done with famous or known by a lot of people or anything like that. But simple to use and maybe adoption from any kind of society, from rich to poor, from modern to traditional people, it still can be done with fiat. Will need really long time and maybe small chance to happen for crypto to be global currency. Maybe digital fiat will be used first.