If you come to my country, in my state, my town, you will see big sign boards advertising gambling sites. From this you will understand that the government does not care.
On TVs, YouTubers and everywhere you will see gambling site advertisements.
What will betting agents do if someone send under 18 to place bet for him in such town like mine? There is nothing that can be done in countries like mine than to teach your children the right and the wrong. Let them know the pros and cons of gambling and how bad a gambling addicted person can be.
I have recently mentioned it in another topic: in my country, on the contrary, there are regulations in force to protect the youngest, like a minimum distance between schools and the nearest casino, the mandatory identification in order to access, the prohibition of advertising them on billboards and bus shelters, and also of advertising them on TV before 1:00 AM. Even YouTubers have been warned and will be fined if minors are among their target and they advertise anything related to bets.
Therefore, I think it depends more on the culture/politics/government of each region.