No country has taken bitcoin as a legal currency for general transactions because of the complications that go along with it. It cannot be adopted yet in that way because it is still too volatile and for now, the transaction fees are too high. Imagine if you were at your local grocery store and upon paying your bill, you would have to pay almost half of your total bill just to process your transaction and on top of that, it takes hours to confirm. Also, since bitcoin is very volatile and its possible that upon paying, the price would change. It would still be a hassle to use.
bitcoin for small transactions is not very profitable, and there are still a few countries that allow bitcoin to transact at home, but if transactions are on a global scale and there is trade between countries then bitcoin will be very profitable, first a non-convoluted system does not require third parties in transacting and which are guaranteed to be very secure, then bitcoin is only suitable for large and global transactions, so bitcoin becomes an alternative currency.