I highly (and regularly) recommend reading Gabor Mate's "In the Realm of Hungry Ghosts"

It's an enlightening read on addiction that will make you more empathetic for addicts of all types: gambling, substances, shopping, whatever.

Definitely worth a look if you find yourself asking "Why don't they just stop?"

https://www.amazon.com/Realm-Hungry-Ghosts-Encounters-Addict...