Ask HN: Instead of intrusive age-check why can't we have "two internet"?

Let's say I'm a parent with some kids, they each have a smartphone and SIM cards, and so they can connect to the internet.Why cannot the internet/phone provider place them on an "alternative" network with alternative defaults, like kid-friendly DNS and what not? Since the age of the customer is likely to be known at the subscription time.At home, you would need two connections, one "normal" and one kid-friendly, with another default DNS. You can select which one is the default that would be picked up by the Ethernet cable. Then you just need two wifi network, exactly as you can have "guest access".Am I being too naive or would this solve like 99% of the problems at very low complexity cost?

Excerpt limited to ~120 words for fair-use compliance. The full article is at Ycombinator.