I think in this digital era it is very difficult to control the activities of teenagers, because just by having a smart phone and having an internet network, they can do whatever they want. Because anyway, even though the government banned gambling, the reality is that many influencers promote gambling themselves. Sure, many influencers have been arrested for promoting gambling, but the reality is that gambling itself has been publicized so underage children will still be able to access it. So yes, any rules to limit the age of gambling, I think it is never effective, because the reality is that the gambling industry itself also continues to increase.
Age restrictions work relatively well when it comes to physical casinos, since they have personal on the ground checking people out and if a person that looks to young to be on their establishment appears they will immediately ask for an identification, but online this is very different, we know that most casinos do not ask for anything related to your identity until you attempt to make a withdrawal, so a teenager can gamble and lose everything and no online casino will do anything to stop it.