It seems that using Crypto is illegal in many countries. Because it lost so much of the government's interests. They can not control it, resulting in many bad things happening like tax evasion, money laundering, illegal transactions, corruption, etc. So the best way is to ban it.
Many countries around the world prohibit cryptocurrency because they can not manage transactions and exchanges in the crypto market, which makes governments feel very difficult to manage. But still many countries have adopted Bitcoin and cryptocurrency as a kind of asset and payment, used in many services around the world.