For video games I was a casual until I found a genre that clicked for me, and kept me wanting to go back to that world and gameplay formula. what keeps someone coming back will vary person to person, but for me in short it was a combination of the story, art direction and gameplay mechanics.

Before that I could get really invested in a game, but jumping to a similar one would easily burn me out. Finding your thing can take a lot of trial and error, and like you said for some people is just not worth the time / money investment.