Epic poetry not a cultural universal

We normally think of the monuments of epic poetry - such as Gilgamesh, the Iliad, Beowulf, the Niebelungenlied, and the Mahabharata - as foundational to every civilization. Yet some preeminent cultures, such as those of ancient Egypt and pre-imperial China, have no primordial epic. Why is this so?

With a few learned exceptions, such as Vergil's Aeneid, the written phase of epics is normally the distillation of the remains of a massive groundswell of oral poetry. Most of this oral creativity has not been recorded as such, but we have good evidence of it worldwide. So the key question is the presence or absence of the epic effulgence, if you will, not how many manuscripts we might now have of some particular specimen, As far as i can tell, this ecology of creativity, abundant elsewhere, did not exist in ancient Egypt and ancient China.