I'm a counter example to this. I've stayed for a long time at my parents. I also had gaming addiction. My parents let me do whatever I wanted. In part, this was because they recognized that they didn't have the knowledge or wisdom to tell me what to do. All they could do was to provide me: love, food and a roof over my head. We all knew this.

One big difference though is that I come from a family of abuse and they scared the living hell out of me by showcasing all the addicts in our family and their educational obtainment. So for me, school was a flight to safety, despite being game addicted as well. At the time, game addiction wasn't a well understood thing. I barely scraped by in high school, but I got into university.

University felt much more like a game to me anyway, so I decided to gamify it and make a whole game out of it. Then studying at university became my addiction.

Oh, and I was still living at home all this time.