We're at the point where we replace our phones every two years, and plan on letting our kids use the old ones. (Probably wifi-only, mostly to keep costs under control.)
I'm not to worried about social isolation. This will vary from person to person. The article mentions all the fun things the writer did when she was a teenager. However, when I was young some kids were addicted to gaming on there 486 or 8bit NES, never met any friends. The tone of the article is a bit 'in the old days everything was better'
Not having a phone will cause some isolation as well. A lot of meetups with friends are announced on app-groups. That was actually the moment when I decided to buy a smartphone myself, when I started missing out on parties.
But you know what? My kids aren't babied. My oldest and I just went to a two-day rifle shooting clinic, and the two oldest have knives of their own that are very sharp and that they can use whenever they want.
They hike in the woods by our house, unsupervised, and they ride horses and swim. They climb trees. They camp in a tent in the woods by the house.
As for their peers? Those poor kids have never even touched a sharp knife, much less been given one of their own. My kids are well aware that they're allowed to take a lot more risks than their peers, and that they're given more responsibility for their own safety.
They're not babied. Rather, the kids who stay indoors on a gadget are the ones who are babied and stunted. They're the ones whose parents have infantilized them.
A kid doesn't "deserve" a smartphone. What they deserve is a childhood. They deserve to be bored for long stretches and to have to make up their own games and stuff to do. They deserve the privacy of their own thoughts, and to not be tethered to a gadget that they can't put down. They deserve flesh-and-blood relationships, instead of jerky pixels and audio. They deserve a life, and not just an existence.
1. No phones at dinner EVER
2. No electronics (of any kind) except low music on school nights without explicit approval or when the device is being used specifically for school work
3. Free reign on weekend electronics outside of prior commitments and all chores are done
Weekends roll around and you would think they would be glued to the electronics based on everything people post here, but usually it ends up being a last resort. They would much prefer to go play soccer with friends, practice their artwork, go shooting or give each other facials.
I suspect you use the knife example as an analogy. My daughter has a hatchet. It scares the heck out of me. I don't let her use it when I am not around or children other than our own are with her. But she loves it, and I have attempted to teach her correct and safe usage.
Technology can be as dangerous as a "sharp knife." Being given safe and monitored access to it and becoming familiar and comfortable with it will likely result in a more positive and healthy experience with it when unfettered access is suddenly thrust upon them.
I spent some time learning about the family sharing and child restrictions available on the iPhones. I've been pleased with it. She only has the bare minimum apps and a couple educational ones (no social media yet, restricted web access), and is not able to add any without authorization by a parent on the account. We plan on allowing her to earn entertainment/game apps with good grades, etc. She reads like crazy, so we don't restrict access to books borrowed for free through a library app.
She is actually without it this week, as a result of discipline (nothing terrible, but an excellent bargaining chip we didn't have before). Great responsibly comes with bigger consequences.
I am not sure how we will handle instances of loss or damage, which are sure to occur. May have to contribute monetarily, work it off, be without it for a while, etc.
As other have mentioned, it is a fact of life now. It is important that they adopt the technology that is pervasive in our society. They need to be comfortable with it and have a healthy relationship with it. It is a large part of socializing now, which, again, is important to allow in a healthy, responsible way. I would rather be an early, involved part of that to help steer it when it inevitably goes slightly off course.
Edit: To add, I believe that as parents, our best teaching tool will be the way our kids view us using our phones. When, for what and how often. And I suck at it. I am way too prone to pulling out my phone and flipping through a feed at any idle moment. I know I need to set a better example. But we do have strict times, such as dinner or in certain social settings, where we don't. We need more of those times, and it is always a rewarding feeling when we do an activity as a family where I realize I didn't bother or even think to glance at my phone for hours. It is good to seek out more of those experiences, and our kids notice it.
That said, I would consider giving a young teen or pre-teen a cell phone to start teaching them how to use it in a healthy way rather than deny them entirely. Very many adults have addictive phone habits and you can't keep your kids from making their own choices forever.
Next year he goes to high-school. I'm considering what he will and wont need in that scenario.