That just sounds like lazy teacher discipline in class. Decades ago we couldn't even use calculators on some tests, but now (or up until recently) they could practically have a computer in their hands all class?
1. Required teachers to have kids turn-in their phones for the duration of each class period
2. Banned teachers from kicking kids out of the class who did not turn in their phones.
Teachers don't enforce the rules here because they don't believe the administration will have their back if they try. They can assign detention for students not listening, but many students don't show up for detention, and meanwhile that student still has the phone.