Answer:
The young man's ultimate powerlessness
Step-by-step explanation:
Anderson's describing the young man as "a leaf blown by the wind through the streets of his village, "a thing blown the winds," and "a thing destined like corn to wilt in the sun" suggest the young man's ultimate powerlessness.
This clearly means that as the fallen rusted leaves of trees are helpless and powerless against the winds of the village and they are blown in whatever direction the wind takes them without having a say, the young man is the same. He has no power and no say.