> but both instances required exceptional conditions and the use of very durable materials, papyrus paper and dried and protected clay

Note that papyrus is not a "very durable material"; it's an extremely fragile one.

Papyrus records survive in Egypt, and only in Egypt, because nothing ever spoils in Egypt no matter how fragile it might be.

Cuneiform records survive all over the cuneiform-using world because they are very durable if you set fire to them.