Do you have examples of this trend being a thing? I can't think of any, at least regarding warfare - there were no exceptionally good soldiers who could turn the tide of battle millennia ago just as there are no such thing now
The military has an entire branch dedicated to the concept of "exceptionally good soldiers", it's known as "Special Forces". To an extent, it could also describe soldiers who are good enough to be allowed to use advanced equipment that's a cut above the rest, such as pilots who get to fly F-22's and B-2's.
If they were useless for affecting the outcome of battles and wars, then militaries wouldn't bother with investing in such groups.