Why does Homer refer to Agamemnon's return from Troy?

Homer refers to Agamemnon's return from Troy to highlight themes of heroism, betrayal, and the consequences of war. Agamemnon's homecoming is marked by tragedy, as he faces betrayal from his wife, Clytemnestra, which serves as a cautionary tale about the dangers of pride and the fragility of glory. This narrative contrasts the fates of different heroes, illuminating the complex interplay between personal relationships and the broader impacts of the Trojan War. Additionally, it sets the stage for exploring the themes of vengeance and justice in both the "Iliad" and later works like the "Oresteia."