In the UK we have the NHS and the only way to get into rehab on the NHS is if you are a single mum or are homeless. Otherwise you pay for some private facility. We also don't have the prescription opiates that American's take for breakfast, elevenses, lunch, tea and dinner so the problem is not a full on crisis here.
From the anecdata I have I believe that coming from a broken home, not knowing whom your father was and childhood trauma is a large part of it. Drugs are 'always there for you' and work predictably, therefore a relationship with a drug is kind of preferable to maintaining real relationships, with a partner, with friends, colleagues or family. I believe that addicts that go through rehab to then work with the addicted, vulnerable members of society stand a much better chance of living a worthwhile life, even if their 'family' becomes the intake of addicts at the place where they work that 'family' is pretty good compared to the empty and pointless life that is addiction.
Everything you think you know about addiction is wrong | Johann Hari
Honestly, addiction is a difficult problem. A lot if the time it's good for people with similar problems to get together and work towards a solution. It's not always easy to tell who's a good actor. For example, some rehabs take mostly indigent low-bottom drinks from off the street. I'd imagine that they have a much higher rate of relapse just from the population.
Ultimately I think it's tied in to a lot of similar social problems, like poverty, mental health, homelessness and prison issues. In general, the US just doesn't value improving those things very much. Which is sad.