> It is very important for a designer to recognize all the parts of a design that are not easy wins, that is, there is no proportionality between the effort and the advantages.

In optimization, if you make an analogy between speedup / improvement with advantages / effort, you get Amdahl's Law:

https://en.wikipedia.org/wiki/Amdahl's_law

"[T]heoretical speedup of the execution of the whole task increases with the improvement of the resources of the system and that regardless of the magnitude of the improvement, the theoretical speedup is always limited by the part of the task that cannot benefit from the improvement."