It's not a "one size fits all" issue. There can be differences in insurance coverage's time a person can be in. I'm sure things have changed over the years since I worked at the mental health clinic, including with the MICA population. But it was cut from 90 days to 30 then, and a month isn't enough for many people.
In patient programs, including coordinating with family and/or community services, will differ. Every staff member is an individual with a specific skill level. Every person being admitted for care is likewise an individual, with a level of insight unique to themselves, with different goals, and different support systems upon release. Hence, outcomes range from recovery to utter failure. And even in recovery, a person with addiction is at risk of relapse -- for addiction is a disease with a significant relapse feature.
Many people benefit from participating in community support groups. Others do not. And there are those who quit without rehab, support groups, or legal problems. In my opinion -- whatever it may be worth -- the current list of drugs available to abuse or even use exactly as prescribed complicates the issue even more. Certain drugs alter the brain's functioning long-term, not limited to periods of use/abuse. For example, I worked with people who never carried a diagnosis before, who then have significant periods of cocaine abuse, correctly be termed bi-polar in recovery. Others do just as much, quit, and are fine.
While it is an individual thing, there are certain risk factors. These range from the age when one started "partying" to extended family patterns.
Great question! It brings focus to very real issues that confront our society.