:)Bitcoin was launched in 2007. It's 12 years and still no country has approved Bitcoin ?? Huh
and in 2018, 2nd richest man "Warren Buffet" said "bitcoin will end up badly"

Its just a matter of time when countries will start accepting crypto currencies. Once we hear from big countries the support for bitcoins, all the other countries will follow it and it will be accepted everywhere.
I am sure there will be no country that wants to use Bitcoin to replace the country's currency, but if there are countries that legalize Bitcoin as a trading tool, many countries have legalized Bitcoin.
Countries are looking to launch their own digital currencies, instead of using bitcoins. But once people will start using local digital currencies, bitcoin will gain more popularity and become more expensive.