The more I dwell on this (not much thankfully!) the more unsettling I find it tbh. I've been trying to put my finger on it, and I think it's the selfishness that gets me.
I know you don't see it as that, and at first glance that might seem OTT, but on reflection I don't think it is.
It means putting those around you through more effort, whether that's by printing out hard copies for you, phoning about sick kids rather then a notification, requiring separate messages re parties etc.
It means more inconveniencing strangers if you are lost, or need to know when the next train arrives.
It inconveniences your children -it limits whether you can go, the flexibility you have, where you can park even. It reduces their opportunities for social interaction. It'll mean then turning up to cancelled events because you can't keep up with the pace.
It means you can't catch a taxi/Uber when the bus is cancelled.
If you go on holiday and it turns out to be a complete hovel, you can't go and expand you and find the nearest reasonably priced alternative.
Your car breaks down in the middle of nowhere, how do you even know where you are? I mean you might have in car sat nav, but if your car's broken down, that might not be working.
All these inconveniences are fine for you because you've chosen to live with them. I feel its selfish to expect your children to.
You don't need to become a screen addict, the fact you've lived all these years without a smartphone means you've got that self-control to begin with. You don't need to have it on you all times, but having access when you need it. It's just a part of modern life, wish you are unilaterally opting your kids out of as well.
I don't know if you've ever watched race around the world. I think it's pretty naf, but most of their difficulties come from not having a smartphone!