You are bang on - I keep meaning to write a book called "The Problem with Middle" (or I could change 'middle' to 'average' using your wording). It is where the most competition lies, where resources are at their most scarce yet it is where the majority reside!
I think that part of the problem is that we're hard-wired to follow the herd. We compare ourselves to others and then end up homogenising into a single group of commoditised average-ness!
It is brave to step out onto the fringes yet this - as you note - is where the inner and outer rewards lie.
We also encourage average through society in many ways to create easy control points for both evaluation and management.