Studies show that half of 11 to 13-year-olds have seen pornography at some point. What's missing from that stat is where they saw porn. Reddit, Twitter, Instagram, Imgur, etc are full of porn but aren't technically porn sites. If that's where kids are accessing porn then blocking porn sites will not fix the problem. Unless you understand what the problem actually is there will be no way to fix it.
Soon, we'll see "Studies show that the legal requirement to verify users has led teens to master using VPNs."
It's adults that'll need to learn. I foresee a lot of awkward conversations with parents trying to ask theirs kids how to set up VPNs while pretending it's for a different purpose.