Anyone who needs to understand addiction can go watch Trainspotting, or even just its very beginning few minutes with the "choose life" speech, which is what basically made it "click" for me. It's basically about how certain paths to ruin are so fun for certain people that even when they realize they're on such a path, they don't want to stop walking it. Sometimes, that walk is so much fun that even after they stop walking it they realize that a long, stable, healthy life just isn't worth giving up on feeding that addiction. It's a whisper that stays in your head forever and intensifies during moments of weakness, which is why those 12-step programs are permanently ongoing affairs with a "sponsor" assigned to you to help you discourage even after it might seem like you're "cured" to outside observers.
Considering how big an issue addiction is in pretty much any given part of the world, it's probably important for everyone to understand at the very least that addiction is a fully distinct thing from chemical dependency, if only to avoid sounding ignorant in public. Probably avoid even remotely sounding like you're blaming them too, since that'll just get people to shame you as a group, whether you're right or not.