If Bitcoin was the currency of a country, that country would have gone a long way economically. However, as you say a country as a currency, operating Bitcoin will reduce a lot of corruption. But I think corruption can increase a lot if no proper action is taken from the government. Suppose you have one lakh Fiat coins. You can easily transfer through Bitcoin elsewhere. That is why it can be said that a scammer or corruption person can make big transactions through Bitcoin. But yes it has many good aspects such as using Bitcoin of all will increase a lot of resources. And citizens have to have a high rate of education so that no complications are encountered.
You are speaking on realize profit but right now, if there is any country that use Bitcoin as main currency, there is going to be a lot of controversy surrounding it. If you have noticed Blackrock Bitcoin movement, you will notice that the market is bullish when they are buying and the market will be less bullish when they are experiencing sell off, if such country that hold Bitcoin start selling their Bitcoin, it's going to make Bitcoin plunge because of sell pressure.
Bitcoin need to be a decentralized assets and not some that some group of people will want to control, it's not good for the decentralization of Bitcoin. There could also be problem from world bank you know, no country can be independent unless you want to make your country suffer just like the way North Korea is experiencing, organizations like world bank will not help them when they need help and can you run country without loan, obviously No.