You could be in the finest school in the world and the phone would still win.
Also, France started doing this a few years ago already and has seen improvement across every metric. Better grades, more socializing, 80% less bullying, less anxious kids. They only downside they found? Parents complaining they were unable to call the kids at any moment.
A large part of this can be avoided by giving campers an entry time based on the location they have on the campsite. Now it's a free-for-all which means pushing and shoving until it all stagnates.