I can certainly believe that's true because opportunities which can be solved by top-down process-driven progress can be addressed by market leaders and leave little opportunity for startups. Though I don't know that a sample of superstar companies makes for a definitive dataset. I know of multiple companies no one has ever heard of who are dominating their niches (that no one cares about, until you hear how much money they are making), and the most important factor to me looks like risk-taking, good positioning, and good timing by the leadership, not anything special in terms of technical achievements or flexibility by employees.