There are emergencies the adults at the school won't understand. This has happened a few times to my spouse, where the nurse/teachers kept brushing off issues they didn't understand, ranging from things like asthma to strep throat.

Otherwise, I agree that the phones should be put away during class.

I hear you. But my child will have a cell phone in case of a real emergency when the adults don't properly act. While I trust teachers rather implicitly, my experience with most school administrators is far less stellar. Also, a student calling 911 when the teacher is having a heart attack or some other life threatening event will save time and possibly their life.

Barring any emergency situations, my child's phone better be put away.