I think gambling sites only want huge profits with the number of members playing on their sites, regardless from of the data used for Kyc real or fake so far, because their dont care about age limit rules , I think to prevent minors from gambling should be the main responsibility of parents at this time, although it may interfere with their activities but parents should take the time for regular supervision, such as Monitoring children online activities regularly can be done without must to stop working, like checking browser history and using monitoring tools if possible.
That would be a lot of work to do, and it will come to a point that it would be impossible to monitor. Suggesting's easy but taking action on it is hard trust me.
Even the authorities are having a hard time knowing which of the gamblers are minors because it's hard to know which is which. As for the KYC, it's even hard to know if it's real or fake right now with how easy it is to edit one and with the help of AI, it's even harder now. Regular supervision from parents would be advisable as always, but you can't do it 24/7 and at some point, these minors might still do it. As for monitoring your children on their online activities, that would be good, but it's hard to implement.
I don't just like what you said though that gambling sites are only here for profits. Like, that's why we are creating a business, right? To make money. They can lower the number of minors playing on their site, but you can't completely eradicate it because at the end of the day, there will always, and always be minors playing on these online casinos.