You need to understand the basics first, if a government legalized the decentralized cryptos then they will not implement another thing called their own cryptocurrency aka CBDC. Basically the central banks tokens are here to fight with the decentralized cryptos and just wanted to ensure there will be no freedom to use our own money.
I honestly don't see that even as a fight. As long as price stability is pegged it's just too centralized, and anything too decentralized doesn't have a fighting change against Fiat money as they are not designed for same use cases. Inlfation in fiat money is acting like a buffer to the whole country stable. While cryptocurrencies are not designed to befenefit a one country. Also the scarcity could influence our economic behaviour how we currently are spending money.