The thing is, there will most prolly not be a good relationship between Bitcoin and governments, and that's basically just cause Bitcoin is decentralized and governments like to work with only centralized services that they can control either completely or to a certain extent, it's quite clear to governments of today that it's impossible for them to get a foothold on Bitcoin, thus they will rather sanction/ban/regulate it than adopt it.
Having said that, as far as a country's economy is concerned, I think there are very few ways Bitcoin can be of help, Bitcoin is money and you'll most likely need to have money in fiat to get Bitcoin or offer one service or the other to get it, it is not distributed for free, and even if many citizens of a country hold Bitcoin, I don't see how it can positively affect the economy. It's the duty of the government to provide what is necessary in order to improve their economic situation, if the government does such, then Bitcoin can only be an addition.
One reason why some countries still didn't make a decision whether to make bitcoin or cryptocurrency a legal tender is because they don't have any control about this decentralized platform however it is amazing to know that El Salvador adopted this digital platform legally in their country. I believe that cryptocurrency is one of the way to boost of a countries economy but this would also take time to implement in an economy because the government bodies will surely take time to review and study the pros and cons on the said platform.
Cryptocurrency can indeed be a source of income, therefore it makes sense that countries that legalize cryptocurrencies will increase their
economy. But to improve the economy of a country with cryptocurrencies it can be done but it does take time and patience. Because cryptocurrency
does not provide instant profit, but must go through various kinds of processes that are quite long. El Salvador is an example of a country that
strongly supports cryptocurrencies, El Salvador does not mind that Bitcoin cannot be controlled. El Salvador still makes Bitcoin a legal tender,
even though many big countries don't have the courage to legalize Bitcoin. Hopefully El Salvador can prove to other countries the economy has
improved since legalizing Bitcoin, so it can be followed by other countries.