Trust me porn is no where near over saturated there is plenty of meat left on the bone.
The only problem, as I see it, is the number of new surfers coming to the Net for porn has fallen, the number of quality sites has risen and the porn buyer is more savvy.
So the days of this just being a numbers game are over for most, the newbies will pick up that market and as you say work for a level that most can't live on, $1,000 a month.
For the experienced, the talented and the established the way to go is quality and volume traffic. Make sure the surfer sees something better, it does not have to be different. I've been shooting trhe same thing for decades and it still sells.
Am I worried about some guy in Moscow picking up a camera and starting a content store? Give me a break, unless he can shoot like me why should I care. The more newbies the better, makes the good guys look even better.