A lot of people don't get things until they experience them themselves, and before they get to experience something themselves whether it's a loss or anything, they will simply keep ignoring the advice and everything given by others because they think that others might be wrong and the experience might not be as what they are describing. However, at the end of the day, when they see it themselves, that is when they regret that they should have listened.
I used to stop people and advise them about gambling and the addiction and that they can't really earn money from it and will eventually lose, but after some time, I realized that it's useless and I'm wasting my time and energy on something that isn't going to give me anything. If they don't want to listen, let them face the consequences and they will eventually understand.
If you can stop people and advise them about gambling and addiction, you will help them avoid losing, especially if they don't have good self-control, which can trigger them to gamble continuously. This will be useful for them because when they are addicted to gambling, they will no longer be able to be advised by anyone. If they can be advised, it will not be easy for them to accept because they will be resistant before they finally accept it.
But if they can take advice from other people, that's good because at least they still care about themselves. They want to prevent themselves from experiencing loss and becoming addicted to gambling. That means we have really helped them to avoid problems that can arise from gambling.
Yes if you can do that it's great, because those who are addicted will be helped a lot by some of your suggestions, but I think for those who are already addicted it might be very difficult, because as we know they have their own mindset in gambling, and obviously their perspective in seeing it is far from normal, in the sense that usually they are too excessive so that they can enter the addiction phase. So for those who are already addicted, maybe you need a lot of time or hard work so that the advice you give them can be accepted well, as you said that they can no longer be advised. It's okay if you want to advise them with the aim of helping because it's quite good, so with you I hope they will consider some of the advice you give especially in the problem of losing.
It's quite difficult but that doesn't mean it's impossible, that way maybe they will realize slowly. And well usually those gamblers who are already addicted must first feel a significant downturn before finally thinking that this is really a bad habit that only causes a lot of problems, so after they experience that I think there is a chance of awareness for them to stop.