If we assume that access to the Internet will be made in some remote place, then all these problems will not be solved, because if we are talking about the global use of cryptocurrency in society, then people need to be trained and this should be done not only in the institutions, but also in the initial the school. until there is a more global approach to this problem, Fiat will remain for daily use for a very long time.
I believe that fiat currencies will not be defeated by crypto currencies, because it is easier to use fiat money than digital money. I tried to imagine if a child under 5 years had to pay using digital money to buy candy, the child would be confused. But if the child uses fiat money, it is easy to submit to the seller the right money to pay for sweets.
From the parable, I concluded that crypto money would be a companion in the modern financial system, where people who have intellectuals would easily use it. But people who live in poor or underdeveloped areas are easier to use paper money.