Many people confuse true friendship with other manifestations of interaction between people, such as acquaintance, neighborhood, common temporary interests. I agree with you that a true friend will do everything in his power to remove a friend from gambling as soon as he notices the first manifestations of gambling addiction, even if he hides them. An acquaintance or neighbor by and large will not care about someone else's gambling addiction, so he most likely will not take any steps to help the person who is in trouble.
Addiction is not something that can be easily removed like a cloth that is on someone neck. Gambling is a desire to make money by investing little amount betting on different games. Sometimes you predictions will end up giving you some winnings while sometimes you will end up losing huge amounts of money.
The consistent playing if games without discipline is what normally lead to gambling addiction.
You could have an addiction and still able to control yourself when it comes to betting while their are still people that find it difficult to control their gambling activities because of the curiosity to make more than what they have invested. Gambling should be out of emotions because their are times when you will not always make the kind of profit you have anticipated.
Someone who is addicted will not be easy to recover, because in my opinion the problem is their mindset, even with the help of a psychologist, this is not easy. And yes, people who seem addicted can be seen from their behavior in gambling, for example when they experience defeat and cannot accept it, then the option they do is to want to bet again, it seems that they are included in the group of people who are addicted, as well as when they win and do not immediately withdraw the winnings but still want to get more wins, this is like a step to becoming addicted.
You are right, what you said is that games that are played without any discipline will cause addiction, this has happened and the evidence is that there are quite a lot of them who have experienced the destruction of their lives quickly because they want to get a victory that is actually uncertain.