And this is where meaning is relevant. Good naming is important to convey the level of abstraction. What you describe is as if you were to compare the functioning of, say, the liver, by looking at its cells. Proper naming conveys what you are looking at and you can chunk things together. If all the functions are named at the same level of abstraction, of course the code will be much worse to read.

If all the names are just a and b, well, of course it is harder to follow the flow of a program because the use and meaning of the functions has to be infered by their definition. Good names help identify paths of flow, but I rarely see this separation in a clear way, resulting in the problen you describe.