[hn_throwaway_99]

This is a bizarro statement than any historian would laugh at.

Slavery, in lots of different forms, flourished for nearly a millennium and a half throughout the world after the fall of the Western Roman Empire (including, quite conspicuously, in the Eastern Roman Empire for nearly another thousand years...) It's very strange to me that you consider slavery responsible for the downfall of Rome given how it was so prevalent everywhere for so long after.