For me, it's not smartphone addiction but video addiction which can consume hours of my time, just watching on sites like Twitch.

I was inspired by the recent Hacker News thread that talked about decreased attention span https://news.ycombinator.com/item?id=31874846 (My awakening moment about how smartphones fragment our attention span)

My hypothesis is using phone for reading books is much better since it can be done in chunks at a time and is less addictive than watching video so I'm using my smartphone for long-form book reading.