To be fair there was infrastructure then that doesn’t exist now. Most phone boxes are basically just public urinals now for example, I mean they always were but you could usually expect a phone to be in there too. People were also used to remembering numbers, but the only numbers I remember these days are my own and various landlines from my childhood which have been disconnected for over a decade as people did away with traditional landlines, then the VoIP bridge replacements which just became a way to receive international tech support scam calls more efficiently.

I personally want to see smartphones curtailed more generally; if I had absolutist power a lot of the adtech sector (at least surveillance-based behavioural recommendation algorithms) would be legislated out of existence on public health and democratic integrity grounds for example. I’d like to see e-ink smartphones become a wider market segment too, as these inherently break a lot of ‘dark patterns’ and also make short form video content less viable in favour of text content. I don’t think we can just take smartphones off kids and dump them at eighteen into the psychological manipulation engine that is the modern adtech sector without wider structural reforms to our relationship with smartphones and the internet.

I'm a man with a very particular set of skills...

A parent is more likely to go rambo and be helpful than cops or teachers, just look at past school shootings where cops didnt do jack sht

You don't necessarily need to take it away, there are other avenues of punishment. Detention, Saturday school, no extra-curricular participation, suspension, etc. I was in high school right as dumb cell phones started to become a thing and those were our punishments if we were caught with phones out. We were allowed to have them, but they had to be either off or on silent, and in our bags (same as CD/MP3 players.) We were allowed to have them out to check them only during lunch and before and after school, or if we had to make a call, in the main office. I completely agree that kids shouldn't be using phones AT ALL during class time, but there's ways to allow them to exist and punish inappropriate usage that doesn't require teachers taking them. Teachers shouldn't be taking phones, that's a liability risk and not worth the effort.