The fact El Salvador accepted Bitcoin as a legal currency does not mean that other government across the world will accept it someday. The reality is that , the government will keep fighting bitcoin with all market strategy and strick regulations.
No, that fact means that other countries will accept Bitcoin because they have been looking at El Salvador and this country is doing well. There are also some other countries that successfully implement Bitcoin as payment means. To prove you wrong, I want to give you an example of Louisiana state government. This state in the USA accepts Bitcoin payments.
Reasons why they will keep fighting is not about the prosperity of the people majorly but about power and authority to control people. This is why they prefer the centralized system in order to keep the people poor so that they can run to their feet for daily bread, seek shelter and wait for other provision.
We all know that through Bitcoin, every one will be there own boss. No control or submission to any authority over your own belonging or money, the life threatening taxes will be done away with.
But as of now, no matter how popular Bitcoin becomes, it will keep facing the wrath of the angry government who need to keep people poor.
More also, before bitcoin will become used by everyone across the world as means of payment, most users hear must have grown white Bear,
They want to know who earns how much and what's the source of their money. I don't think they want to get rid of Bitcoin payments because it's what's stopping them from becoming rich. Governments usually are anti-privacy and that's the reason why they want to know everything about their people, to stay in power for a long time and get rid of the opposition.
Btw Bitcoin's adoption is inevitable for any country, it's the future.