It's more complicated matter, cause we apply here to the question what basic idea lies behind the cryptocurrency. If we focus on the aspect of decentralization, then governments don;t have anything to do with crypto. Although, if we describe crypto just as virtual assets, then government may use this idea to promote itself as modern inistitutions. But let's be honest, such approach will be similar in shape to Libra all newly announced Venus, and in its very base it will be just stablecoin based on national currency, so using it won;t be different from paying with credit card.