Cryptos are great inventions but they can never replace fiats. They can be used as an alternatives of fiats but, they will never take place of fiats which are backed by powerful governments. Bitcoin and every other cryptos has privacy issue and as Andreas said "If you had that kind of situation with Bitcoin, it would be a problem. You might receive Bitcoin from someone who received it from another person, and that person received it from someone, who stole it from Mt. Gox. Then some exchanges can say, that they don’t want this Bitcoin and they may even shut down your account.", it is not likely that people may trust them wholly.
However, they are the single tool in the hands of ordinary people whose freedom is on stake.
It was a nice interview.