Although Bitcoin is a decentralized technology, it is not immune to the reach of governments. Assets need authorization to be traded and due to this situation, regulations will emerge in several countries.
Yes it is decentralized and you can use it in any country whenever there is an internet connection. But its better to be recognized by the said country and being supported. This is also for the benefit of the people to curb fraud and illegalities surrounding it. Governemnt is only on the regulation side.