Reality today is a bit different from what those old Fiqh rulings assume. If you look at it in isolation, the mukallaf ruling still applies, but when it was made, humanity and especially Muslims were in a whole different state. Today, most people are wage slaves, both parents usually work, they're basically forced into the situation this riba system dumps on them.
That means parental supervision duty has turned into a real hassle in this setup, and in a bunch of other details too. Plus, the extended family that helps raise kids barely exists anymore. A lot of Islamic rulings haven't adapted to this modern situation. They're just not practical like that anymore.
On top of that, in education systems there's usually this pressure to keep up with new technologies, so a lot of teens end up pretty much unsupervised with them. We're living in completely different circumstances now.
I know there are a ton of holes to patch up, but you gotta start with the most practical and doable ones right away. Otherwise, I'm no fan of the state sticking its nose into every private matter. But try telling that to the parents of teenagers who got a motivation for a crime or suicide from ChatGPT.