In my opinion, it is a foolish idea to create a state crypto currency. Since the main purpose of the cryptoworld is independence from the government
it is the technology and being open source means anyone can use it for anything they like. the main purpose of bitcoin is being decentralized, independent and all that but this is not the purpose of cryptocurrency.
the main purpose of a cryptocurrency is to be a currency based on cryptography which brings speed, security and easy control. this can be very useful in a payment system too which is why a lot of countries/banks are looking into it.