A propos, there was a review on slatestarcodex for "Secular Cycles" effectively tracking the rise and fall of civilizations if I remember correctly. The argument is societies start to destabilize and stagnate once wealth concentrates to a certain point, after which war and strife levels the playing field once more. Except, we don't much expect that same sort of upheaval to happen today in Western society.

All of which to say, you could liken periods of high wealth concentration as lending to decadence, though I'm not sure how useful that would be as the same argument could be made of golden ages. Decadence itself doesn't seem suspect but I would expect it to be around before things go awry.

edit: here - https://slatestarcodex.com/2019/08/12/book-review-secular-cy...