How much of this time is glancing at the phone while
- sitting on the toilet
- sitting on public transport, commuting to work
- walking somewhere
- waiting somewhere
You can *easily* spend 4hrs with such activities. Basically, many people use their phone during activities that cannot be spent for anything else anyways.
What about people who drive to work and have the phone on for Google Maps? That drives up the screen time.
What about people who take tons of photos of their young children (like me). Drives up screen time.
Those screen time numbers sound unbelievably high - but there are many ways in which they might be inflated - and your suggestion that all that time could be used for something better is most likely wrong because most of the screen time happens during times when no other activity can be pursued.
Of course, during such idle time humans should be *actually idle* and allow the brain to rest instead of bombarding it with dopamine, so those screen time numbers are still horrible no matter what.
