The purpose of the Iliad: Schrott finds the answer
in the Assyrian great king Assurbanipal (668-630 BC) and his large library in Ninive. Assurbanipal collected all the literature known at the time in its capital Ninive, which he wanted to make the successor to the cultural metropolis of Babylon, destroyed in 689 BC.
Schrott now believes that Homer created the Iliad for Assurbanipal as an ethno-graphic work for his library in Ninive. He may be thinking here of a comparison with Herodotus, but this idea is not plausible at all.
The Iliad is a star catalogue, I will explain that later.
But Homer is also a great poet. And great poets bring a new cultural identity into an artistic, a poetic form.