The big issue underlying gambling, betting, alcohol, tobacco, and other addictive stuff all the way to fentanyl, is that people may literally lose their mind over it, at least party. A heavy addict ceases to be a responsible adult who can act reasonably and autonomously, and becomes driven by impulses they cannot control, like a schizophrenic who cannot control the voices in their head.

Even more unpleasantly, this does not happen to everyone every time. Quite many people can have a glass of wine here and there without becoming alcoholics. A ton of people can play a game like Bejeweled out of boredom, and happily switch to more interesting activities, given a chance. Some people can voluntarily stop even taking heroin and subject themselves to therapy. Etc, etc.

But a relatively small minority gets hooked badly. They cannot quit. They do not want to stop. The addiction becomes a primary life activity. Many more who could be hooked to physiologically brutal addictions like nicotine or heroin are wise enough to never approach those, understanding how badly it might end. But again, a relative minority cannot resist the lure.

A less tolerant society would stigmatize such outcomes, adding strong social pressure that might keep potential addicts from getting into the habit. A society could also consider addiction a medical condition that requires intervention and treatment, like poisoning or a dangerous infection. Even modern Western societies are capable of that when sufficiently frightened, see COVID-19.

Another approach, which I'd call "extremist libertarian", would just let addictions form, proclaiming that this is what people do exercising their free will. It would not be different from a complete lack of civilization, and leaving the problem to the evolution to solve. In either case the addicts would suffer, in worst cases going destitute and die. That would remove the addicts from the gene pool, probably lowering the risk of addiction in future generations, slowly. Slowly, and painfully, often not only to addicts but also to people around them.

We struggle with addressing addictions because we struggle to admit that addictions exist, and that in bad cases they affect the sufferer's agency quite a bit. I'm afraid that without admitting this property of heavy addiction we won't be able to act in an efficacious way.