The reason why the most glorious and developed city like Troy was destroyed is a very subtle one and Sri Aurobindo explains it at length. If any part of society develops too much at the expense of others, then Nature has a tendency to bring it down so as to ensure a more holistic development. The fall of the developed part is inevitable for the balance and growth of the whole society which must hence evolve together and in a more complete manner. In case of Indian context, the great war of Mahabharata crumbled the collective egos of the isolated elite class that is Brahmin and Kshatriya after which a new society emerged. The whole Greek society, apart from Troy, was almost barbaric. After the Trojan war, the importance of Reason was established, second thing was the increased importance of beauty and truth and love, the third was the emergence of democracy and fourth was the freedom of individual. Achilles was the hero of war and he is listening the message from the messenger to whom he had sent to Troy. Though the answers from Troy are a denial and supposed, we witness here a change in the ruthless warrior’s mood. He seems to have grown through the years and a seed of compassion begins to develop in his heart.
Death decries all Ideals as a vain dream, an illusion that can never be realised upon earth.