My guess (haven't read the book): humans are social creatures, and too much company with just our own thoughts is not healthy in the long run. It might not caus

My guess (haven't read the book): humans are social creatures, and too much company with just our own thoughts is not healthy in the long run. It might not cause addiction by itself, but it's definitely a disrupting factor for mental health. Interaction with other humans can help to interrupt unhealthy thought loops and help people to reflect on their state of mind.