Parenting is really one of the best ways to give awareness to the child so that they will not get exposed to gambling activities at an early age, which lead to addiction and doing bad things. But not all parents are like that; others are too busy with work, and others can't guide their child well, which for sure would be the fault of parents. That is why we should give time to our children, tell them what is good and bad, so that they are aware of it, and keep an eye on them.
Although some kids do get a good parenting background, but sometimes they get tangled with friends influences. They can have a different lifestyle outside, and when they go back home, they pretend to be good kids. But it depends on kids and their decisions; anyone who decides to be responsible will heed what their parents teach them. Although what you say is also true, some parents are mostly concerned with their job and forget the family responsible, which is mostly concerned with raising the children in a way they should grow. Again, gambling addiction can start at any age; it doesn't matter whether one starts their gambling activity at a very young age or not; once someone just decides to lose self-control over doing something, it becomes an addiction, which can lead to other problems for the person.