I see your view and appreciate the time you’ve taken to articulate it well.
My view takes another level of abstraction from it, and ignoring the implementation detail for the moment - the question for me is “what are we trying to protect underage/vulnerable persons from?”
Sex is a natural thing and I’m not arsed either way - and some of the more extreme content (within the legal sense, non-consent and animal porn etc are another ball game) such as exploitative content or covertlyy recorded stuff really need to be addressed as society issues so that the ensuing pornography isn’t such an issue.
That said, the line defining the three (or more) groups is arbritary and different for everyone I guess.