If a person who is addicted to gambling realizes that he is addicted to gambling and he should come out of this addiction but he tries to come out and if he has 100% effort then surely he can come out of this addiction.
I have yet to see anyone who was able to get out of gambling addiction. Gamblers get out of gambling when they are in too much debt and don't have enough money to gamble. Only then do they take a break from gambling.
You have not seen doesn't mean no gambling addict has been able to get out of the addiction. Addiction is not to a death behaviour that can't be cut off if an individual is determined and also having the support of family and friends in eliminating the addiction. It's not easy though but it happens. Sometime about addiction whether gambling or any other form, it takes a gradual process and that's why we should learn to be patient with anyone battling to come out of it, encouraging and counseling them when and where necessary.