If being free from compulsive gambling were in the victims hands, a good number of them would walk out of it immediately. But since the players can't control decisions anymore, they'll need help to be safe. Only few addicts took the problem solo and solved it, but a lot more of them who wouldn't do same, are not to be blamed.
I think the problem should be prevented before it gets out of hand. Like its always said, prevention is better than cure. No doubt, a gambler who is addicted has lost control over his emotions and mentality when it comes to gambling. The gambler understands that what he is doing is problematic and causes harm to his finance, emotions and relationship but actuality can not help it.
There are a lot of addicts who struggled with the addiction until they were wrecked to nothing. It is always in the interest of the gambler to stay responsible and resist the urge to chase wealth through gambling. It is this shift in mentality that can help the gambler avoid compulsive gambling where the gambler as you mentioned would find it difficult to cope or overcome the problematic in gambling.
As far as I know about 1-3% of adults suffer from a pathological tendency to gamble. It's a clinical diagnosis, so they can't get rid of their disorder on their own no matter how much they want to. They will gamble as long as they have money. No amount of prevention will help them. Only specialists can help such people, and no one can guarantee that after treatment they will not return to gambling again.