It's very hard as from time to time there are changes with your adrenaline and you keep pushing and trying to win more which being produce by your emotions, without a good control on it, the chance of losing more would be be the outome of your session, better to pause for a while and stop your gambling session, assess yourself instead of keep trying to win back.
Taking a break and stopping the gambling session is what he should do immediately before all his money is wasted on gambling, and he will regret seeing it. However, it is difficult to stop immediately after experiencing a losing streak, and it takes time to master self-control. But if he is willing to learn it and practice it, he can stop gambling immediately and even leave gambling immediately after he experiences a loss or win. He will feel he is better off stopping for a moment and leaving gambling than he will repeat the same mistakes he has experienced before. That's where he can learn from his experience and will not repeat it because it really makes him experience even more losses.
Yeah if the person still in his good mindset that should be the reaction knowing how dangerous it can be if he will try to push forward, he will just repeat the same mistake if he will not stop, after all he already knew how it feels when you do regret to waste your money into something that not really allocated for, gambling as part of entertainment is okay but if you made a mistake and waste more money better to stop and not to continue as chasing your previous loses will simply add more to what you need to recover.
Well that's the problem, it seems very appropriate to say "it's easier to say than to do" that's the right statement for those who only say they want to quit but not by taking any action, it seems that the reason they say that is because they have lost a significant amount for them so they get upset and say things like that, not at all a promise and it's just nonsense, and also none other than because I have friends like that.
Basically, it's hard to quit if their little heart still wants to gamble like you said and I agree with your assumption. I think they only have a chance to stop if they experience things that can make them really bad, such as losing a very large amount or in terms of their family falling apart due to economic factors that are destroyed due to gambling, in conditions like that, usually they in my opinion will really be able to think to be more aware or at least reduce their gambling activities. Of course, after all gambling is only an activity for entertainment, always nothing more than that, and as a result for people who carry the wrong mindset, it is clear that they will suffer a lot of adversity there. So the point is please be more rational in looking at things so that you don't fall into the trap.