The same applies to porn sites. If an 11-year-old boy visits a porn site from his cell phone, he is asked: Are you over 18? He clicks yes and that's it. There would be a very easy way to control that but it seems that our rulers even consider healthy that kids have access to porn of all kinds from a very young age.
As for the gambling sites, you have already been told, those that do not have KYC requirements something similar happens. At most the only thing they ask you to do is to declare that you are over 18 years old or to have read the T&C (where it is said that you have to be of legal age but almost nobody reads it).