Today many countries accept bitcoin as a virtual currency, is it because bitcoin is so high that they think bitcoin can change the country's economy, or because the country has many bitcoin users already?
Possibly it can be if and only if Bitcoin users among that certain country will use their Bitcoins responsibly to come up into a desirable one to contribute into the growth of their country's economy. Bitcoin will not certainly do manage to rise up of the country if people will not do any actions about it because the economy is not that directly being affected by Bitcoin since people are the one who manages and uses it for different purpose.
Currently, the government can take advantage the educational level of the cryptocurrency user to earn tax through exchange. You have to know most of the exchanges are needing to verify KYC to register account trading or at least have more capacity to withdraw money from exchange. That's the advantage of the government at current.