the government will not fully control cryptocurrency, but both in the future will co-exist, in other words, most governments in the future will be able to accept digital currencies to be used as alternatives for various transactions without having to eliminate the fiat function itself
I doubt it because government will feel threatened considering allowing two currency to coexist and one which is not in control and decentralized could potentially hurt their economy. the uncontrollable currency is a huge disadvantage for the government considering that they need control over everything to let things run as they were planned and crypto will become a hindrance.