On a global level, El Salvador will be closely monitored by all other nations. The bigger economies will see this as an experiment in order to either adopt or shun bitcoin completely. It is both exciting and scary at the same time.
True, El Salvador has taken a big step, if I'm not wrong Japan also legalized bitcoin, but it's still a drop in the ocean. Countries like the US and European UNION would be decisive if they ever passed a law that would allow clear use of bitcoin anywhere in these countries, they currently allow bitcoin use, but they don't have bitcoin laws and many other countries follow what US and European Union do, if the US legalized bitcoin I think many countries in africa (including my country) would follow the same path. but unfortunately the presidents that the US has had in recent years are not in favor of bitcoin
Bitcoin isn't illegal in most countries but there is a difference in it being included in the law as a legal tender. The implications are different. For example, in the 'Bitcoin Law' by El Salvador, one of the articles states that bitcoin 'must' be accepted if offered by the customer. So if you go to a market and say I want to pay in Bitcoin, they have to accept it. Furthermore, to help the merchant the govt. is going to facilitate so that they can instantly swap BTC for USD at the point of sale.
USA wants USD to be the global reserve because they literally control the supply. I would assume, even in an ideal world, USA will be the last to adopt.