That's just sad.
i'm not claiming not to be a heavy user of my smartphone. I have a curious mind. Things pop into my head all the time. "Where else have I seen that actor? (this happens a lot when watching TV)" "What were Fran Tarkenton's stats?" "What's on that restaurant's menu?" Yesterday, one sudden curiosity was "Why do some people think vinyl sounds better than CDs? (interesting answers actually)" I pop out the phone and look it up.
Now, when I'm in a restaurant alone having breakfast or lunch, I'm sitting there like all the other drones, eyes focused on the little rectangle. It's the modern newspaper.
But I don't need the thing to live. Like I said, when I'm out with friends, I leave it in the car or at home. I interact with my friends. When I'm biking or playing golf, or taking my dog for a walk, I don't carry it (unless I'm on-call for my job). I don't need or want the interruption. I'm old enough to have experienced life pre-mobile phone. Quite often I was incommunicado for many hours. Yet here I am, alive and well 25 or so years later. Sometimes I'll ignore a call and get questioned by the person later, "Why didn't you answer?" Any my response occassionally is, "I own my cell phone. It does not own me."
There was a time when I was never without my phone. Maybe part of that was the newness of the tech. At some point, I decided that it was just a kind of weird to be so glued to this thing. As I've said, I'm a bit of a contrarin. Maybe it was just seeing people everywhere - in restaurants, parks, cars, theaters, stadiums, concerts**, etc. - all glued to their phones and not engaging in the world around them. I gradually started carrying it less. I still have it on me most of the time. It's rare that I drive somewhere without it. But I've become much less tethered to it and it's a good thing. Try tossing it aside once in a while. You might find it liberating.
** The concert thing really bugs me. It seems like the majority of the audiences these days are more concerned with recording the show on their phones than in actually watching the show. So they pay perhaps hundreds for a ticket, really don't pay attention, and at the end of the night have a phone full of video with poor sound quality that they might show a few minutes of to their friends in a "Guess who I saw last night!?" boast. Just bizarre.
I still hold to my position that leaving one's phone away from you is one of the dumbest things one can do.
Nearly everything is tied to your phone number. Nor would I want to try to attempt to recover my information without my phone.
It's the modern wallet. It's also a lifeline, should one need one when walking a dog or biking.
I think part of the issue you have is the loss of general etiquette with phones. That, I can understand. I turn on "DO Not Disturb" when I'm in certain situations (theatre, opera, movie, etc.). Phone automatically goes into Driving mode when I'm driving, so I get zero notifications, and it kicks back an auto response.
I can't fathom NOT having a phone with me at all times.
And that's because it's not just a phone to text and call or message or search or take photos. It does that as well.
It's how I pay for things. It's my banking tool. It's my transit pass. It's my vaccination card... my insurance card... my pharmacy card... my gym card... my movie card.... my Starbucks card...concert/event pass...
Like I said... it's the modern wallet.