> Some supporting evidence comes in the form of writings from the earliest authors we can find, who explicitly claim that they descended from more advanced prior civilizations, who fell due to big cataclysms. This story is actually quite common.

It's hard to know to what extent Golden Age and Age of Heroes myths were rooted in or developed out of real events, but by the time many of these myths were written down civilization really had collapsed across the Near East and Mediterranean some 800 years earlier [1]. The Late Bronze Age collapse was in many ways more catastrophic than the fall of the Roman Empire 1500 years later.

But the civilizations that fell during this time period were civilizations from which we have ample evidence like the Mycenaeans (who may have been the inspiration for Greek Golden Age myths), not some mysterious civilization that had invented Segway scooters tens of thousands of years in the past.

[1]: https://en.wikipedia.org/wiki/Late_Bronze_Age_collapse