Kids also cannot sign up for internet service, or pay for it. So in both cases, we're talking about society gating access to something, adults obtaining that product legally and bringing it into their home.

The question, then, is who is responsible for the children in the household? I've always answered this exactly one way: the parents. Power and responsibility must go together, so if the parents are responsible, then the parents must have the power. Parents have been held legally responsible for the crimes of their children, and given the coverage of parents being arrested for letting their kids go on a walk across town, I'd say this sets up incentives pretty well.

But all of that is a sideshow; a narrative. What we actually have is a massive swing towards authoritarianism globally, largely fueled by in increase in the internet allowing for unprecedented surveillance overreach, and the folks trying to seize control of those reins are using children seeing porn as a way to seem benevolent to garner support from folks that don't understand what's actually happening. Huge swathes have been duped into believing the narrative and fighting for age-gating in the worst possible ways, and that's because they're missing the larger pattern.

It's manufactured consent.

Kids can access the internet in all kinds of places outside the home, and outside the purview of their parents supervision. Schools, libraries, friend's houses, public wifi anywhere.

You may be right about the authoritarianism; it's a tendency of our species and makes it all the more remarkable that Western freedoms have lasted this long. I think, though, that it's more likely simple greed. The giant tech companies, dependent on ad revenue because nobody would actually pay for what they are offering, must be able to track and profile people.

The "protect kids from porn" lobby has always been around, it has nothing to do with surveillance or the internet. These people would be picketing a bookstore that sold Hustler magazine back in the 1970s, and demanding that customers be made to prove their age.