Crypto currencies are fundamental to any country’s survival in the 21st century. Just like how good was valuable 200 years ago, we can safely say any country which did not accept gold made a mistake. The same can be said about crypto currencies.
Completely banning cryptocurrencies will heavily damage the global value, and it will deprive people, especially traders, of possibly high amounts of income, which will reduce consumer spending, therefore slowing down the economy.
The only reason you would want to ban cryptocurrencies is because you are mad other people are making money and have so much wealth when you are struggling to pay rent.