Bitcoin does not need to be legal tender to be used. If you think that it is prohibited and people can not use it in countries that it is not legal tender, you are misunderstand it.
Bitcoin is for underbanked and for everyone, in every country.
Legal tender is only one of things to bring Bitcoin to more people on social media. I think Bitcoin will be get accepted more without legal tender. However El Salvador is a good test for the world.
We will wait for the effects of legal tendering in El Salvador. If they succeed, Bitcoin will be welcomed all over the world. This is an important turning point for the future of Bitcoin and the future of crypto.