I don't understand (2); I (and probably you, too) never had a phone going to school, or playing outside, or doing most other things, and this was fine. If you really need to get in touch for the rare emergency that will probably never happen you can just ring the school. I sometimes see parents talk about not being in contact 24/7 is like [1].
On a practical level, "no phones at all" is just so much easier to enforce.
On a practical level, "no phones at all" is just so much easier to enforce.
[1]: https://www.youtube.com/watch?v=MJP4dr_mioA