Many gambling sites on the other hand which are created for the purpose of scamming people will not even have KYC at all, they will just the gambler if he is 18+ and that's it. Any kid who learned how to read can simply answer yes just to be able to enter the game.
I think this is where the government should focus on stopping, those small businesses that are making money through their illegal work, but they don't want to catch them because they will not make money out of them. They will just simply close their business and create a new one. If possible, they should be prevented from creating another by imprisoning those who are behind it.
However, minors these days know how to go around such requirement, like they can borrow ID cards from their older siblings or sneak the IDs from their parents. That is why you need to instill values to your kids at their early age. This will be your weapon even if you are not around.
Do remember, illegal casinos will always be there. They will only stop their operations when someone reported them and forced to shut down their site. But as long as they can do their business, they will.