I agree that stopping your addiction is actually a choice but the problem is that the choice is really hard to make and its not that they don't actually want to stop or they don't know that this act can destroy them, its just that some of them lack the will power to actually stop this habit because an addiction is really hard to stop especially gambling and drug addiction and most people are even an addict of both.
Yes it is true that it is a choice that must be taken, after all sometimes it is strange why they can't quit their addiction, for example I am a cigarette addict almost every day I finish 2 packs of cigarettes or even more but on the one hand I have been a cigarette addict for quite a long time , but for the sake of my health I tried to reduce it slowly and was determined to stop. after a few months I quit smoking until now almost 3 years without smoking.
Many people are too much with their addiction as if they will die if they don't do it, it's just about mindset, I always thought that I would not die if I didn't smoke that's what made me quit smoking, let alone gambling, it's obvious that I can overcome by reducing and changing the mindset so you don't become an addict, it's hard but I'm sure everyone can do it.