In my opinion i cant agree with thing, that cryptocurrency can change fiat mony on 100%. Do you belive that goverment of Europ and USA will allow crypto? I think no.
And who will ask their permission? If a critical mass of people who support cryptocurrencies will be recruited and cryptocurrencies will be used in online stores then no government will stop it. People do not understand that the government was created to serve citizens and not Vice versa.