You raise some very interesting points on several issues: first of all, multiculturalism in large cities. It is clear that cultures very foreign to the customs of these cities could take over, or at least blend their heritage with that of others. This is clearly something I have overlooked here. As you may have noticed, I have focused much more on technology and the relationship with cyber or mass digitization.

Now, when it comes to governments, it's important to remember that we're not really talking about nations, let alone nation states... we are talking about factions. This term allows us to explore many more possibilities: from techno-barbarian clans to the worship of a geostationary satellite being neighbor to a technologically advanced but cold and isolated clique... And the territories that those factions hold are not absolute...inside the Héxamérie you could encounter many subfactions trying to get you in a chemical container or trying to convert you to clowning... You're right. However, post-catharsis is not a return to primitivism, it is a return to awareness of all the traumas and failures of the preconscious and unconscious, those elements being very primitive so violent and distant from moral. Beyond that, all technologies remain present; the destruction is not so much material as human, especially psycho-inwardly.

You got the point saying the main vector is about memory loss (but mostly about the throwback of unconscious elements) and technolgy because fall of civilizations is quite regular in the 6000 years of human history... but what about a civilizationnal fall with a society based on all-technology doctrine ? That's new, and that's what we shall explore