Each gambling addicted is different. Being gambling addicted isnt something uncurbable and does not mean that everyone will ruin their lives with 100% probability. I think everyone who has tried gambling at least several times are already addicted, because they return to gambling anyway. We have different forms of addiction, someone return and gamble daily, someone on special occasions, someone gamble once each month. But that does not mean we all are moving towards ruining lives.
Addiction is a manifestation of human weaknesses when a person cannot stop in time and this applies not only to gambling. A person by nature is prone to find hobbies for himself, and sometimes these hobbies can be too addictive. For those who play sometimes, as you say once a week or once a month, this is definitely not an addiction, especially since I even admit that such players can win, so it is not worth saying that gambling is bad. It is bad when a player stops controlling his actions in gambling, in the same way you can lose self-control in other hobbies, so these are individual qualities of a person. We are all adults and no one is able to make decisions for us, you need to be responsible, then everything will be fine.
Good point, self control is important. Your hobbies can easily lead to an addiction if you are not in control of yourself. This is something that you enjoy doing so it's possible for you to get obsessed with it. Personally, I think that there are certain things that we shouldn't take as hobbies and one of them is gambling. It's true that it's possible to just do it passively for fun but to be on the safe side it shouldn't be a hobby.