That and cases of teenagers assaulting teachers that dare take away their phone. For many teachers it’s not worth the career and physical risk. If kids don’t want to learn they are not the enforcers. They didn’t buy these kids the phones.
And what of the kids that do want yo learn if the phones are causing disruptions and promoting an anti-learning culture?
I think the lack of discipline (not just punishment, but more order and integrity) in schools will only worsen the societal problems we are already seeing. Is there any reason to think that allowing kids to be thugs in school won't lead to them being thugs in life?