..and movies, books and TV?

No: all of those are "single use" items, i.e. you typically only consume them once.

Games and social media, OTOH, are designed for continuous consumption without end. Here, "being addictive" is basically the only thing that matters (and in fact, is the only variable companies actually measure).

A problem with that model is little kids do what feels good and what feels good is watching the same TV cartoon many times. Once they're socialized into adult life they stop. I distinctly remember when little kid cartoons (tom and jerry type stuff) became boring and repetitive to me so I stopped while my kid sister was still cool with watching endlessly repeated stories.

And at the other end of the age scale, my MiL watched (watches) MASH (a 70s sitcom about the Korean war, which sounds improbable but was actually hilarious due to good writers) and she never, ever laughs, quiet as a church service, but I'd LMAO at a funny line I'd never heard before, and her entire family would stare at me like I'm insane. "But don't you get it, it was hilarious, Radar compared the other guy's wife to ..." and they'd just shush me like in church. I'm not entirely sure what she's thinking when she sees episode #24 for the three hundredth time. I should ask her over the holidays...

Something that both anecdotes fit is the model of not being in adult society or caring much about adult opinions.

This is why I've stuck with single player games. Aside from a summer where I spent 12 hours a day on Counter Strike, I only play single player games enough to just finish the main story (don't care much about unlockables or anything crazy). I finish them and that's it!

I've never actually played an MMORPG. I avoided EverQuest in University when everyone was playing it. I never got into WoW (I did have a friend who lost his virginity to a girl he met on WoW so...I guess it helps some people).

I feel religiously opposed to them now when I see how involved people get into those games. I'm all okay with Quake/CounterStrike/Left4Dead type games where you shoot-em-up with a team for a bit and then it's over. Those are good breaks when you've been on a project for hours.

Movies and TV yes (there's ample research to show it actually rots your brain). Books, no. There's also ample research to show it has several benefits, even if you're reading trash. The medium is the message, as Marshal McLuhan would say.