Answer:
The usage of a single fixed pulley would be desirable because it is an easier way to lift and transport a heavy object from one point to the other in meanings of elevation.
Step-by-step explanation:
A single fixed pulley is a very smart and simple mechanism that changed the life of human beings because it allowed us to move heavy objects in elevation dimensions with easiness. It might still represent a considerable effort but is simpler than lifting it with the body, also because there were places that required to lift objects but didn't have stairs to transport them over them.