...There are still some rural places in this world, so it will be hard for them to adopt the new system if this will be implemented in the future, which I hope won't happen, and even those person in provinces will also get mad if those things happen.
Many countries have now started developing their national digital currencies, which will have to replace their national Fiat currencies. In order for cryptocurrency payments to become available in hard-to-reach places, we only need access to the Internet.
The digital currency of states can largely supplant paper money, since they are of the same type by nature and differ only in their carriers. Apparently, this will be so. However, a decentralized cryptocurrency has no chance to replace the national currency of states. She is not capable of this, and no state will ever allow this. Cryptocurrency can only exist along with the national currency of states and they can complement each other with their capabilities.