El Salvador's future since becoming a legal tender is still a mystery, they are still on the experimental stage and its outcome is not yet confirmed. Other countries or places in the United Arab Emirates, Kingdom of Saudi Arabia and Singapore is also looking forward to become one of the legal tender but they just cannot fathom the risks for now and chose to observe El Salvador's outcome first before taking a huge leap.

And for the bitcoin to become the world currency is not yet possible in the next decades to come and I reckon that it's not also created to be like that. Just like what you've said, the governments of each respective countries aren't going to allow that to happen as there's no way that they can control it as it's also not designed to be controlled.