I don't think it won't happen. There are some countries that either online gambling or non-online gambling is strictly prohibited or in short, banned. Try to do some research and you'll understand why I said it though there are a situation where a country banned gambling and yet decided to unban gambling or making it legal in that country. Yes, it is true that they can't stop cryptocurrency but the government can ban crypto while if a person caught using crypto will be put to jail. My country does not ban Bitcoin and there is also a custodial wallet/exchange that you may use to trade, buy and sell crypto but it is regulated by the central bank in my country. In short, they find a way to earn profit from people who owns and use crypto through their regulated platform or service.