The color is part of it. I put a greyscale filter on my phone and it’s insane how much it’s reduced the device’s ability to suck me in and keep me staring at it.

The original Game Boy and Tamigotchi weren't colour, or backlit, and they were disruptive in classrooms when they came out. For at least some individuals, even simple black and white, non-networked games, are kind of compulsive. This is probably particularly true for younger children without guidance.