I am in the same boat as you. I am not a big "fan" of only fans.
Why pay money for that when you can either find it for free, pay to see someone in real life, or Cam site and talk one on one with someone. Granted camsite has run its course with me as well.
But with OF i have noticed like you.. it is repeat of the same thing. Not long enough vids, just thong and bikini shot type stuff, etc.
I also personally think that it might be "fading" away as well because of what we are seeing and also with the fact that you see more and more and more "discount" codes people are pushing to get people to stay on the site or to get new people involved.
The top models evolve and the others will fade away with anything.... be it camsites, OF, fansly, manyvids, etc. Same goes with escorts as well. What i mean by evolve with escorts is that they change with the times, keep providing stellar service, being punctual, good communication, etc. The good ones have staying power and are awesome.