collapse of the old society

Not the best article, but it certainly is a symptom.

Interestingly, crass social divides seem to be a much more common and often civilization defining characteristic as explained in Graeber and Wengrow's "The Dawn of Everything" book, where they show many historical examples of local communities that primarily defined themselves in opposition to their neighbors or predecessors. The MLs don't like that part of the book at all as it directly contradicts their holy scripture that is largely based on material determinism.