I found this expression on the news channel about the crypto currency: "Anyone who will try to buy coffee for cash in 2023, runs the risk of causing laughter from the seller, that he does not use crypto currency."
how do you think, is it realistic? Can a crypto currency replace national money?
I think that it's possible, but it will take more time.
I do not think that crypto can replace national money. Majority of people may be using cryptocurrencies in the future but national money will still be the main currency for everybody. Everybody may recieve payment digitally but fiat will still be the main currency.