I must say it could be very hard to entirely eliminate gambling from the source of the world or from those country that highly frown gambling, even if those gambling site are no longer functional there could be a way for them to gamble, two or more person could team up together to gamble so easily, and they could both stake money to gamble and whomever wins takes the cash from the rest. Most time they can easily inside to do that or in a place where eyes wouldn't see them as they are gambling, most times people gambles in a club where party is ongoing you would see people in other Red rooms gambling where no one could easily detects they are gambling over there. Even those countries that tends to ban gambling are still gambling illegally some could uses VPN to access some of those gambling site.