The moralizing coming from all angles is weird, since everyone involved would probably consider themselves a problem-solver.
I got a PC that was all mine and an ADSL internet connection at 16 years old, before of that I used the family computer, but not really used the internet a lot since back in the day it was quite expensive, and when I did I was monitored by my parents. I got a smartphone that was capable of accessing the internet everywhere at 18, before of that only a phone that did phone calls and SMS. And still grow up fine and managed to get a good career in IT.
There is no reason whatsoever for a child younger than 14 to use the internet on its own, without the surveillance of his parents. And there is even no reason for him to have a smartphone. If as a parents you are concerned about giving him a phone for emergencies, just give him a 10$ feature phone that can only do phone calls and SMS. It's as simple as that.
Nowadays kids are always in front of a computer or a phone, they no longer go out to play, instead they spend their time on Tiktok or other stupid social media. We must change that, not the internet.
It can be very hard to enforce unless you are a stay-at-home helicopter parent who homeschools.
Peer pressure (not just on the child, but also the parents) and the need to fit in will result in your child demanding their own device by like eight at the latest, and mounting pressure to do so. (Apps are part of the curriculum in some places now!) And failing that they'll just buy and hide their own device by like 14. Though as you imply, if they aren't capable of self-regulating by about 14 you've probably already lost.
Everything from game consoles to the television to the fridge may be Internet-connected. Prepaid plans with data are as little as a single day's lunch allowance in some parts of the world. All their friends have electronic devices with internet access. Along with access at school. And probably some circumvented access at home... it's quite hard to actually keep kids offline.
Every media device in the house is connected to the internet. Every media device in kids' friends houses is connected to the internet. Everything at school is connected and now they need laptops with actual webcams at home.
They're immersed in it daily, and most of the use is unmonitored.
The problem is that parents aren’t trusted to do their job by some and some want the government to step in and do as much parenting as possible. That’s not how parenting works though. The government doesn’t own your children and shouldn’t get to decide how they’re raised.