I have to agree. I'm getting up there too. I'm the second oldest person at my current startup and I looked around yesterday and realized that I wasn't that much more valuable than the 23-26 year olds I work with. I think I'm a damn site more technical than they are, and I also think I manage my time better than they do, but I don't think I provide that much more value to the organization. Especially given the lengths to which they will go to burn through work (i.e. long hours and weekend work).

I personally think that 95% of organizations out there only need/want what the 23 year olds can provide.

I'm holding out hope though that when it comes to truly valuable and technically challenging work that more mid-level to large-ish companies still have teams that value the stability and vision more mature developers can offer. I think this is my last startup for a while.

I think this article hit the nail on the head. It takes a very mature and self-assured person to hire someone more qualified than they are and then hand over the commensurate freedom and responsibility along with it.