I used to chase gear score a lot and it used to be my sole focus. But after enough seasons of having that reset i realised theres only one thing that truely matters long term in this game. Mounts, pets and achievements.
The game may be addictive to some but mainly, it is the person who has the addictive personality. If they weren’t addicted to WoW, they’d just be addicted to something else. Just so happens WoW got to them first.