In those countries, where crypto transactions are not legal, people use the P2P exchanges to buy and sell crypto as in this way, the government does not know that they are dealing with crypto. That's the only option for those people and if you say that they should stop the P2P exchanges, then it means that they should quit crypto and wait for their country's conditions to become favourable for their crypto adoption.
In my country, for example, I do not exchange money on the exchange, but use the services of private exchangers. Here prices are 1-2 percent lower, but it is more reliable.