There are some countries where bitcoin is banned. So can bitcoin be banned? Yes, a government can make the use of bitcoin illegal. Governments can also make trading cryptos illegal, and outlaw the operation of exchanges in a country.
The fact that bitcoin is a global network that is supported by many governments makes a global ban on bitcoin impossible. In addition, it is very difficult to know that a person is making bitcoin transactions, so a ban on bitcoin is extremely difficult to enforce.
Even in countries where bitcoin is a regulated asset, gaining enough information about the people that own the bitcoin is challenging. If a person doesn't use their bitcoin on a regular basis, or takes measures to keep their wallet a secret, even if bitcoin was banned, it would be very hard to enforce the ban.
Some countries have banned bitcoin, and all the crypto-related industries were forced to move to other nations.
The core businesses were not affected by the ban, however they may have been successful is dissuading citizens in the nation where crypto was banned from using decentralized digital currency.
Overall, while bitcoin can be banned, enforcing those laws is difficult, as the system is global in scope.