This. With a phone handy, it’s tempting them into not paying attention, at the very least. The best of intentions can be undone by poor or misaligned incentives

This. With a phone handy, it’s tempting them into not paying attention, at the very least. The best of intentions can be undone by poor or misaligned incentives. And a phone (and a computer to a lesser extent) provides us with the incentive (easy access) to procrastinate indefinitely. Those of us with a limited will power stand no chance.