This is the reason why we have stablecoins. In countries such as China, it is not legal to trade cryptocurrency with fiat currency. So they convert crypto to stablecoin instead. And do you think that all the 200 plus member states of the United Nations would ban cryptocurrency at the same time? Even if it gets banned in your country, you can travel to some country where it is legal and then convert your coins to fiat. International travel is anyway cheaper these days. If you are ready to take some risk, then you can easily do the same using various P2P platforms.