The days of a lone genius making giant strides by picking low hanging fruit are long gone. These days progress is made incrementally by an army of engineers and scientists.
Yeah, but it feels like the size of those increments is chosen so that profit is maximized, but not progress. Before Tesla became a thing everyone thought that electric and self driving cars are half a decade away. They more or less did it in 10 years. And they got most big companies to follow them.
To get back to the example of fusion, no single company has the resources to fund a project like ITER. Even ITER is financed by several countries at once. There are no small steps that will get you from todays nuclear reactors to a fusion reactor (that outputs energy), you are forced to make big steps and focus on innovation.
Speaking of geniuses being rare, I might be wrong about this but it at least feels like that has always been the case. These household names like Newton, Edison, Planck, Heisenberg, Einstein, etc. are pretty spread out over the past centuries. On the other side, maybe we are getting so advanced as a species that at some point no individual can be capable of having the necessary understanding to change the world is a huge way.