I understand the point, but feel it important to note that that's NOT how addiction works. Addiction is not about how good the world is. It is about chemical vulnerabilities of our nervous systems.
People have been getting drunk, high, and stoned, and addicted to the substances that produce the effects, basically forever. What has changed is that we have constructed economies that exploit and punish those vulnerabilities.
In a Utopia, we'd still have addicts. They just wouldn't be homeless and struggling for food and clothing.
Yes and no. We'd almost certainly have a lot fewer of them, and not because they self-Darwinate.
One should generally be careful when extrapolating from animal experiments to humans, but there are still things one can observe. There's a classic experiment when rats were given access to buttons that would provide either pure water or water laced with morphine, and where those rats would obsessively push the morphine button until they OD:ed. But there's another case where someone who had actually studied rats looked at those experiments and noted that they usually featured rats that were just held in solitary plain cages, with no stimulation available
other than the morphine. And that's generally not how rats live in the wild. So they built a
Rat Park: far bigger, with a few dozen rats of both sexes as well as various toys and stuff... and suddenly, the morphine water held much less interest. It's not that it was completely shunned, but it became more of an occasional thing.
In fairness, there have been problems with replicating the Rat Park experiment, and suggestions that the effects might have been related to different strains of rats rather than the environmental effects. But I do think it's fairly clear that addiction is a complex issue, and that environmental effects definitely play a role. Basically, people enjoy getting drunk/high on occasion, but when in an otherwise rewarding context that stays as an occasional thing. When the environment is effed, that's when the drugs become an escape from the effed-up situation and when people become actual addicts.
And of course there are personal issues as well. Some people are more vulnerable to addiction than others. Not necessarily to the drugs themselves, but to the brain stuff that happens as a result. Some manage to channel that "chase for a high" in more positive directions by performing activities that trigger the same brain stuff without the detrimental effects, but that's pretty rare.
