I think another question to complement the thread is whether there's a country whose infrastructure is ready to take up cryptocurrency.
Rural areas with no internet connection is a challenge to implement crypto. I can't imagine how my kid would ran errands to buy something for me from a mom and pop store.  

If people can think of a feasible solution to this, then we should see in the near future crypto replacing fiat national currency.

Adoption should begin with the masses - fishermen selling their haul for the day, vendor selling fish in the market.