Its not the end of the central banks; not in a million years. Infact decentralized cryptos will never overtake central banks. They control the vast majority of currency (trillions). Furthermore ; they can easily build an improved version of the blockchain technology (already happening) and implement it in their system and thus reduce fees allowing them to compete with any cryptocurrency. The only name (crypto currencies trying to act as a fiat) has to offer is "decentralization". Not good enough!