Those are not real crypto-currencies. Those are just digital versions of the fiat currency, similar to Paypal or Skrill. A crypto-currency should be decentralized. It can't be issued by any central bank.
But in fact, the government will use a centralized approach to managing cryptocurrencies. You see that XRP is now ranked second. All of its prices are so expensive because there are governments that support such coins. There are only a few coins that may be scattered in the future, and most of the coins are centralized.