Each country has its own currency, and this greatly affects the country's economic conditions, the higher the value of a country's currency, the more "considered" the country's economy is successful. That's why every country is always competing to increase the value of its currency. The currency of a country has been considered as identity, so if a new currency appears and circulates in a country, then it is considered a threat. The government will not be willing if the identity of the country is changed.

I must admit that Bitcoin's volatility is very high, it's not right if it is used as a currency to measure the price of an item, so if at this time bitcoin is also used as the main payment instrument, it will create uncontrolled price inflation movements. This can only happen if many producers and businesses, as well as humans around the world, make the price of their goods and services using bitcoin, 1 Bitcoin = 1 Bitcoin, not of 1 Bitcoin = 1 Fiat, then many countries jointly recognize and use Bitcoin as a currency, to become the currency of a country around the world seems impossible, the possibility that happens is Bitcoin as a global currency, and in my opinion, it has happened, because the world's currency does not need regulation, it only needs an agreement between users.