Pardon my ignorance, but which countries besides El Salvador and perhaps the Central African Republic have come so far as to declare bitcoin a legal tender on their territories? And the follow-up question would be like this: Does bitcoin actually need the government's approval to become a widely-used currency? I mean those legal tender laws were designed to coercively impose on people fiat currency that naturally has terrible monetary characteristics because it is being printed up out of thin air, and therefore its supply gets continually expanding. In contrast to fiat currencies, the issuance of bitcoin is algorithmically determined, which means each participant on the market knows in advance what the actual supply will be, and they can make a thoughtful economic decision based on this knowledge. But what is more important in this case is that bitcoin value (or, to put it precisely, bitcoin price) is determined by the fundamental laws of the free market, namely supply and demand. There is no place for government coercion in such a market, all attempts to control attitude toward bitcoin via rules like legal tender laws only distort briefly economic reality, which in turn is trying constantly to come to an equilibrium where supply meets demand to clear the market. It is important to realize that a world where bitcoin is a globally accepted currency is also a world in which no one particular has control over the such currency. All attempts to "legalize" bitcoin via legal tender laws are nothing else but the government's approach to making people believe government can control bitcoin, while in reality, they only reconcile with the inevitable.
Bitcoin doesn't need the government's approval to survive. Making Bitcoin legal tender would only increase mainstream adoption, as institutional investors and VCs join the game. But even if Bitcoin is "outlawed", it would still be possible to use it because of the way it was designed. Of course, one would need to be careful when deciding to get into the Bitcoin game in a country where it's been proclaimed as "illegal". If you get caught, you could easily face prosecution from the government (jail time, fines, etc.). To say the least, Bitcoin is NOT a currency adopted by governments worldwide, but it's a global currency because anyone can use it with an available Internet connection. I don't mind about Bitcoin becoming only an alternative than a replacement of the existing Fiat system, as long as it works as intended. Who knows if Bitcoin is still with us decades from now? Just my thoughts