You absolutely need a centralized currency to move huge amounts of wealth from citizens and future citizens to the state in order to build an empire, otherwise no tax-payer would ever spring for such a goal.
All of crypto currency is unstable and unpredictable. Now, talking with BTC, I believe BTC got the brightest future ahead among all other cryptocurrencies, simply because of its performance showed the last few years that excite and entertain a lot of traders and investors.Some are afraid of holding BTC, because its been struggling this past few months and they think BTC will have an undesirable future. But for the bitcoin holders and traders, we believe to that BTC will have a great future ahead.