Are we to suppose that Fabrice Bellard, Steve Wozniak, and John Carmack are merely proficient developers, who are experienced with their stack and problem domain?
well, the latter two of them seem to have created their domains from scratch, back in the day. Now that they are done with the trailblazing and lots of other smart people crowded in, who knows where they stand in comparison to the right tail of the bell curve.