I can't speak specifically for porn (I neither draw nor read a whole lot of it, tbh), but in general, I think the way forward is not to attempt to one-up yourself. Something isn't better because it's louder or more explosive (or more naked!), and if you just keep going louder, you're eventually going to hit a wall.
Lethal Weapon, for example - they tried substituting plot, character development and good writing with explosions, and that's why we're bored with it.
... at the same time, we don't always need to be fresh and surprising - sometimes, you just need to tell the story (or draw the porn, if you will) really, really well. Continuing on the action-movie comparison - Mad Max: Fury Road is, in its basic components, not very original. It's a sequel to an established franchise, it follows very similar lines - Max wanders into a disaster-zone, gets swept up in someone else's conflict, lots of violence happens, he wanders off again - but where it shines is in how those components are put together, and how well they are used.
There are a few novel things in there (placing women as the central focus of the story, not just as targets and victims, but as characters with real agency and personhood), but to be honest, most of it is predictable. It's still one of my absolute favourite movies of all time because it does what it does really damned well. It's familiar, it's something we've seen before, but damn, is it well-crafted.
I guess what I'm saying is that you can draw porn using staple components, as long as you draw it really, really well. ^_^;