For me, it is enough for Bitcoin to be legally accepted as a payment method. It doesn't have to be a legal tender to perform its function. If countries recognize Bitcoin as a currency, that would already be enough.

For Bitcoin to become a legal tender is a long shot, and could even just be considered as an extra mile. Bitcoin doesn't have to be a legal tender for businesses and customers to accept it as payment. I think it is enough catalyst for Bitcoin's adoption rate if a government declares it as an acceptable currency.