By the definition of every major nation in the world, which is that anyone under 18 is a minor, which is a child who should not be intentionally exposed to pornography. Kids shouldn’t grow up viewing content that demeans women and distorts their worldview on sex and relationships, much less having the trusted adults in their lives advocate for them to watch it!!
Very bold choice to argue the nuance of “But how do we define ‘child’?” in a discussion about showing pornography to kids, though!
I don’t think censorship of nearly any kind has any place on the internet, but neither do kids.
It’s a parent’s responsibility to keep their children away from that type of content, not to hand them access to it so they can develop maligned, destructive ideas about sex, intimacy, and women.