That’s a good goal and I think we should aim for that regardless if it fixes addiction. I would not call it easy though. And would it be world without addicts? There are plenty of well connected rich social happy folks who can’t handle simple molecules. Environment is part of the usage pattern but it’s not the only thing. That’s the books point I gather.
You have taken the point someone else made and run somewhere else with it, so I will reiterate it.
> People (and rats) with adequate social lives and decent living conditions are able to consistently overcome addiction
I don't think it's about riches, or power, or having friends. It is purely about how many stressors you have to deal with, how often and with how much reprieve you have available. More money can give more reprieve, it usually means more stressors too.
The more subtle point I guess is that it is not how much you have, it is the shape of your life and how each day feels.
Use the example of far northern countries. People who live in dark countries drink more, and they drink even more the darker it gets. The modern era says that the answer should be more mindfulness, more cognitive behavioural therapy, I think GP is saying we should be giving them sunlight which is clearly what they actually need. Substitute sunlight for whatever thing your locale is currently not managing well.
I recommend the book and the new research. It reflects on the rat park study and makes what I think are good arguments that addiction is not a simple thing we can fix only by fixing the enviroment even though it is part of it. OP was asking for evidence so I thought I’d chip in with a modern source. There are no socities that have solved addiction. Obviously it is a gnarly problem.