I think your post and others in here presents a somewhat oversimplified view of addiction that doesn't fully align with what the science says.
You're right in that that environment and individual predispositions (psychological, social, gentics etc etc) play a huge role in addiction — that part is well-supported. But to suggest that substances and behaviours themselves don't have inherent addictive potential is misleading at best and just ignorant at worst. sorry, but many substances — opioids, nicotine, meth, cocaine — absolutely have pharmacological properties that make them highly addictive, regardless of environment or personal trauma.
You mentioned Vietnam veterans and heroin, which is often referenced, but it's worth noting that this case is more nuanced than it appears. Later research showed that many of those soldiers did continue to struggle with substance use, albeit not always with heroin. Also, availability and cultural context changed drastically after they returned home — it's not just that they were suddenly fine because their environment changed.
As for the "90% of people drink and aren't addicted" argument — that doesn't prove alcohol isn't addictive. It just shows that not everyone develops a disorder. But millions do. The same logic would say "most people drive cars and don't crash — therefore, cars aren't dangerous," which obviously doesn't hold up. Addiction is a statistical risk — not a guaranteed outcome — but that doesn't mean the substances/processes are benign.
Lastly, framing addiction too heavily around self-responsibility risks ignoring the very real physiological and neurological mechanisms involved. Addiction isn't just a bad habit or a lack of willpower like many people here seem to be thinking.. it's classified in medicine as a chronic brain disorder. People absolutely need support, structure, and sometimes medical intervention — not just introspection and accountability.... stuff like videogames and porn absolutely can be as dangerous as substances to some people, not direct physically damaging or risk of death, but definitely life hampering.
Responsibility has its place, especially in recovery. But reducing addiction to a mindset issue ignores how deeply it rewires the brain, and that perspective can inadvertently shame people who need help the most.
I argue respectfuly but I studied biology and specialised in addiction therapy before I wound down my career for a less stressful and mentally draining role.