Both great metrics to have, true.

What trouble? Adults don't want to mess with kids (most child abuse happens with close aquaintances, not random crazies on the street), so their biggest threat is going to be bullies around their age, and a parent stepping in will just make that problem worse, so they'll need to learn to deal with that on their own anyway.

I personally have never had an issue going to/from school, other than the typical bullying on the bus. The most likely problem they'd run into is getting hit by a car, in which case they need paramedics and police, not me, and those emergency services will call me once they identify them (and I trust random strangers to call emergency services if a kid gets hit).

The only time I expect my kid to need to call is if they're at a party or something outside of school and need to be picked up because they don't feel comfortable. When they get to an age where that's a thing, we'll have a loaner phone for them to use.

Sure, but short term impacts are generally unreliable, since there are a lot of cases of coincidence, like a good policy having no immediate impact or a bad policy having the desired impact. Longer term studies account for that randomness.

Falling off your bike and cracking your head open or breaking something or whatever. I used to bike through somewhere where not a lot of people would pass by.

Or even worse, get hit by a tractor who didn't see you and not be found until later, which can cause permanent damage. Happened to somebody I know sadly, she is disabled for life now. Yes, the person in the tractor should have been more careful and have seen her, but you can hit somebody with one of those and not notice it.

I also never said they should use the phone to call the parents, you can also call 112 with those.

Right, but if you're in a situation where you need emergency services, chances are you won't be in a situation to call. For the vanishingly low chance of that being necessary (esp. in my case where I take them to/from school since there's no bus service), I trust strangers to call since my area is sufficiently densely populated for someone to see what happened.

If you live in an area where such things are more likely, I absolutely agree that you should be able to make that choice. I firmly oppose any school-wide ban on phones for that reason, I just happen to agree that, generally speaking, kids don't need and shouldn't have phones.

And if you really feel the need for your kid to contact you or emergency services, there are devices like Gabb watches that have only the functions you need. So please, consider those before considering a smartphone.

Kids shouldn’t have smartphones no, but it can he handy for a group of kinds to have at least some kind of phone. Heck even a phone without a sim can be used to call 112.

With nothing else but the blank walls and the cruel clock now students have nowhere else to turn to to pass the time but listening to teacher blab his time-filling spiel. If they're very lucky, the students might learn a single thing that matters before days end, but of course that remains exceedingly unlikely.

Sure. If you live in an area where kids may need to reach out, sure, give them a loaner phone or something, or one of those watches that can only contact a fixed set of numbers (you and trusted emergency contacts).

It is absolutely relevant enough to be published publicly.

Yet you can already see people calling for phone bans...

Yes, because they should've been banned 10 years ago

Based on what data?