Design a scheme that equips parents with better tools to be better parents, rather than one that reduces the scope of parenting responsibilities.
But, for some reason, little twelve year old Jimmy obtaining access to porn evokes some kind of far more visceral reaction in Jimmy's parents (or if not Jimmy's parents, some "busybody" who wants to "protect all the children") than Jimmy managing to get himself a pack of Salem's or a Pabst Blue Ribbon tallboy.
Because right now there's next to no barrier to access compared to Jimmy getting himself a beer. If you keep saying "Your proposal sucks because it isn't perfect and we should do nothing" then you're essentially surrendering to the people who really want facial scans.
This sort of pedantry is really just supporting the opposition.
I think the only thing I actually have any concern about is phones and social media use for kids, and I think that has a much easier solution than any sorting of tracking-BS.