States and central banks already create and in the future will continue to create their own crypto currency. The state will not rely on the decentralized crypto-currency. They can allow its circulation, but they will never actively support decentralized crypto currency. They can rely only on their national centralized crypto currency. It can supplement national paper money.
Among several countries, maybe they are discussing their own digital currency, with features that can be detected in circulation and transaction objectives. Because the government has an interest in that data, to minimize the criminal impact that might be done through digital money. For bitcoin, because anonymous and decentralized, governments cannot track money.