For me personally the difference between screen time and books or board games is the prolonged focus on one thing. When online, I tend to jump through articles, scroll through feeds and switch focus much more rapidbly than during offline activities.
I’d also say the problem with hypermedia is that the production values allow someone else’s vision to swamp out your own imagination and creativity. If you’re reading a static book, you have to visualize your own world. With digital works you can get the full sensory experience. You don’t need to use your creativity as much.
It’s as if all of the movies are using special effects drenched in CGI all of the time.
The time it takes to switch focus during offline activities is much higher. I can guarantee if it took you 5-10 minutes to switch websites, you'd be a lot more fixated on one thing at a time...
You can't alt+tab on real life activities very easily (generally).
