The blame for the normalisation of porn lies fairly and squarely with the Internet. Before that men had to go out of their way to access it so most didn’t bother.
I disagree. The internet was just a more modern medium that could get it out to far more people, far more quickly, without the embarrassment of having to speak to a human to buy/view it, but the appetite and culture was already there, partly fuelled by the availability of 'soft' material at the outset, to stoke the desire.
There are a lot of things that the majority of people thankfully (currently) still see as disgusting, so although they doubtless do exist to be viewed if people of that persuasion know where to look for them, we don't have a global 'culture' where almost all teenagers regularly watch videos of people being beheaded or animals being torn apart and consider it 'meh'.
Mind, having said that, I've never had the slightest desire to watch it myself, but I believe there was a video that went viral a few years ago with actual women actually eating poo, with countless 'jokes' and references made to it - so whatever stage we're at currently, there's always somebody wanting to take that and push the boundaries further and further.