Bitcoin, for now, is not suitable to become a national currency of any country. Bitcoin's value is too volatile so a product or service will always change in price with respect to the price of Bitcoin. Also, a transaction fee is there with every transaction, this is not practical in using in a daily basis. It will be hard for the government to control the scenario. So if a country will make Bitcoin as its national currency then they have to regulate it first.
I quite agreed with you that bitcoin is too volatile to be used as a national currency , bitcoin being volatile will cause inflation in that particular country that adopted it as a national currency and coupled with the fact that bitcoin is decentralized I.e it is not controlled by anybody will even makes it much more difficult to be used as a national currency.
widely that Bitcoin can not be the national currency of any country because Bitcoin is not suitable for daily transactions.