I take issue with the headline, and I didn't see any support for it in the article -- that people simply grow out of addiction. Treatment or not, we can call that process of reducing one's addictive behaviors growth , but I don't think you can find any addicts -- former or otherwise -- their families, or addiction treatment specialists, who would call that process simple .
Damned hard, fucking painful, betimes hopeless, ..., but the most consistent memory from my early recovery was the simplicity of the process. There really was only one thing important: stay clean.
In my own case I aimed for staying clean for 2 years. And for those two years that was not "the most important thing", it was the only thing that mattered. Other factors helped too (supportive family was next most important), but I think I would not now be clean without the simplicity of that bright line rule of 2 years.