For me it’s typically something I can enjoy absent mindedly.
It could be an element of a game I can enjoy without thinking like a solid soundtrack or visuals but not feeling like “losing” is a lose is another thing.
I like being able to shut my brain off and that typically means a lack of story but still having some form of progression.
I don’t think technical innovations relating to realism and multiplayer are essential. One of my favorite games is Hotline Miami which features pixel graphics and while shooters like Call of Duty do have a satisfying gameplay loop I feel like I hit a wall with progression eventually.
Multiplayer and VR games can also require some extra setup which is a hurdle for a game being addictive to me.