Not sure liberalism is the right word.
What you're describing has been going on since the beginning of time. Civilizations are founded, they grow and prosper, then inevitably begin a slide into decadence and oblivion. They grow more chaotic, less moral, their economic power decreases, then they tend to collapse or at the very least go into a long period of irrelevance. What you gleefully describe as "progress" is nothing more than decay. The coming decades will be interesting times. Sad, but interesting.