I’d argue that a complex economy in a failing society is actually a sign of weakness. Lots of nobles and the likes wanting their cut of a pie that doesn’t really exist anymore. So all of that complexity is not really backed up by the reality and you just have a bubble. I can imagine all kinds of roles and professions that just exist to endow people. This also happens a lot in modern society.

I know this wasn’t actually your point but I just wanted to add.