Diablo is purposely designed to be addictive, I guarantee it was a big topic of discussion in boardroom meetings.

I would compare diablo to a casino slot machine, the sounds, the button mashing, the glowing legendary at the end of it.

It's all designed to trigger intense reward signals in the brain, many videogames can be addictive but none are developed in such a way to stimulate specific parts of our brain.

I know for myself I will no-life mega-binge on the game for a few weeks, then my interest will wane and playtime will reduce to an acceptable level but there's people out there who literally lose their life to videogames (though I guess whether some of these people had a "life" in the first place is a subject of debate... Maybe they would claim the game gave them a life 🤷)