I see the good intentions, but it's too idealistic. In many families both parents work and kids are expected to get home by themselves (such was the case for me from 3rd grade onwards). Smartphones are simply a necessity for communication and Google Maps. I can only ever see this working with upper middle class nuclear families with a stay at home parent.
Why would you need Google Maps to get home from school? I have an absolutely terrible sense of direction, but even I can memorize a single route after walking it a couple of times.
Or ... we could continue doing what worked for all of us before being tethered to phones. Communicate beforehand / afterwards / using shared phones (which still exist) and learning to navigate the world using brains.
Almost all of that can be done offline. Pen and paper still exist. Example 1 is more difficult without a phone of your own, I was able to use a pay phone back in the day. Everything else you listed can be accomplished offline, on a computer, or by asking to use the school's phone for 1 minute. I mean, if the accident happened at school, the office may very well contact you themselves.
Yes, it can be more convenient but it absolutely isn't necessary.
The parent comment is almost an advertisement for waiting to give kids a smartphone until they're older. If one truly can't imagine doing any of these without post-2010 technology, then it would be good giving kids a little bit more time building their independence from both parents and smartphones.
Aspirational at best I'm afraid. What happens when the other partner/parent/family member isn't responsible, smashing your plans? Or if the event has a variable end time with no safe care or phone in between? How do you deal with emergencies like school closures that now require every child to line up to use available landlines (my personal favorite experience)?
Landlines are becoming scant in my particular part of my country, YMMV. I rarely even see them in my workplace anymore.
I walked the mile home from school from the age of five. Why would anyone need a map? And I spent all day outside away from home from the age of about eight in the summer with of course no phone of any kind and no maps even though I was tramping for miles through fields and streets. What has changed in the last sixty years that makes maps and communication a necessity?