Wow!!! Interesting and truly exciting topic. Pornography is an interesting topic and where it has gone is endemic of our instant access society. I have found that porn and some of the corresponding behaviors performed around it, are both a problem of access as well as a mental health problem.
Twenty years ago, porn was hard to get and required a willingness to travel to a store, awkwardly look a round in some strange building, and risk being seen by people who also were trying to covertly squire the materials. I think access to unlimited porn as ramped up the speed at which porn evolves the access was the barrier. It was a breakwater for the tidal wave.
That moves me to the mental health side. I truly believe porn is actually a mental health problem and the rate at which it depicts what we would define as deviant behavior has exploded. There is no science behind this, but porn provides a quick fix, dopamine rush for people. People become addicted to that, they need that, the problem lies that like with any drug or addiction, it takes more to get the user to the high, thus the demand for more extreme scenarios. Truly believe it can be a very destructive in people. I also worry as we as a society are exposed to porn at this volume and the subject matter being where it is, we could come to see some of these situations as normalized in our culture.