You just said it. It's a gradual process. Rome wasn't built in a day. Everyone here in this forum knows that Bitcoin is a legal tender already but I guess you're referring to it in a more global acceptance.

As long as those who use it believe and accept it as money, It's money. I don't think it will get to that point where everyone will be forced to recognize Bitcoin as legal tender. No matter how a maximalist we want to be, we should also make room for others to have a choice not to like or want to use it. Despite how influential the United Kingdom is, the British Pounds isn't a global currency. But that doesn't stop those who value and use it from using it.