This is a clear consequence of devaluation of currencies (inflation). It's documented to have happened at least as early as with the romans. The exact same thi

This is a clear consequence of devaluation of currencies (inflation). It's documented to have happened at least as early as with the romans. The exact same things happened that we're seeing now: people made less babies, rich got richer, the middleclass turned into poor(er), most people stopped being productive and switched to rent seeking (owning land and properties became the goal instead of actually making things or delivering services) and so on.