I think it is incredibly difficult. And even in a large urban area like the SF Bay Area. As curiousAZ mentioned above, it gets more and more difficult to stay in shape and more of a commitment....but it can be done.
But there are fewer and fewer available guys who are willing to make that commitment. So the pool gets smaller and smaller.
But there are other issues. I know many inshape guys in their 50s and 60s and every single one of them is partnered. I also agree with curious that the other issue is that many, but certainly not all, of the remaining single inshape guys in their 50s and 60s go for much younger guys exclusively....and I mean much, much, much younger, as in their 20s.
So, masterdefense, I don't believe you made a bad observation.
Before anyone makes the observation that this means that I (or others who also express this concern) am driven by something superficial as looks...just remember that RJ is a community of active athletes. We congregate here because we want to be fit, we are fit or we admire guys who are fit. It's fair that fitness is part of the "chemistry" that drives our sexual attraction and that fitness also indicates an internal discipline and drive that also contributes to attraction (in my case).