They can still make money from it. They don't have to ban it and just impose a regulatory tax that every profit gained through crypto is taxable and has to be declared as income.
In some countries, they're doing this. Instead of putting a ban to crypto related income, they're simply giving their people freedom to get along with another source of income through crypto trading.
I agree with this point. I think civilized countries should give an example to all world and show everyone that Bitcoin and crypto are not dangerous. However, these assets can be regulated in the proper way so people can even pay taxes for the crypto received from mining or trading. Perhaps, Bitcoin can become a second international currency like USD.
Have you heard about Venezuela's experience? They try to relieve the country's economy with the help of their own crypto known as El Petro. There is already allowed to pay salary with El Petro and the prices in the country partially indexed to the coin.