I partly agree. A conceptual breakthrough always rests on a foundation to which many contributed. All of whom, in some sense, contributed. But my reading of history says that the reconceptualization that leads to intellectual breakthroughs themselves usually only involve small numbers of people.

If you've read The Structure of Scientific Revolutions, what I'm saying is that new paradigms are usually created by very small numbers of people. But they have both a foundation and their further success from the contributions of many.

I'm very much not offering an opinion on a great man theory of history in fields outside of science. Your example of the American Revolution is entirely off topic.

I'm also very much not saying that who will contribute what is in any way predictable. At best, the necessary collision of circumstances to make the breakthrough possible is chaotic, and therefore cannot be predicted. Nor did anyone else. The original point a few posts up was that, even if though there might be a haystack of clearly wasted effort, there may still be a needle powerful enough to make up for the rest.