No one that has ever fall into addiction and comes out so easily because addiction is another bad disease of its own, therefore whatever a gambler does fighting addiction should be their major priority and, also when gambling they should be that open to positioned themselves into addiction as it is a major problems while gambling. Whenever greed is overcome then we can say addiction wouldn't have that priorities over a gamblers because they already they have tackled it from the beginning.
Actually, it depends on the level of addiction. If it is still in the low level of addiction, I think a gambler still can recover it himself or by the help of close people. But if it is in the severe level, it is surely difficult to recover. It needs special treatment from doctors or health experts. The gamblers who are in the sever level, they are fully out of control and can't hear any suggestion/advice anymore. They are only obsessed to win the gambling games, they won't care about financial or economic problems.
Yep, being greedy is one of the factor that can trigger to excessive gambling. At the end of the day, this will lead to the addiction because it becomes an abnormal habit. Sure, we must stay away from being greedy because it will bring very bad impacts.
Level of addiction:
https://www.avalonmalibu.com/blog/are-there-different-levels-of-gambling-addiction/