Bitcoin opens many doors of new markets, which would affect the economy of a country, the reason why there are some countries who don't like bitcoin because cryptocurrency controlled by no one and because they don't get taxes. But if governments open there eyes and use bitcoin in its positive ways as possible you would be shocked that the third world countries who opens their gates on bitcoin will become one of the best countries we have ever seen.
You are being too optimistic, bitcoin can help the economy but governments are never going to allow it to become that big, I am sure they are already thinking about making it illegal but they are unable to find a justification to do it but when they do and they will I am sure that we are going to see most countries around the world banning cryptocurrencies.