some of witch would land a crushing blow to technology .
The Nile flooded yearly, but Egypt continued to advance. There may have been a huge flood in the Black Sea basin, but that area did not contain all of the worlds technology of the time. Was there cataclysmic elsewhere; Mesopotamia, China, Indus river valley, Mediterranean?
I think your premise needs to show some facts behind it before you can make a categorical assertion like this. I do not see the evidence for the assertion at all.
Where is the evidence that some sort of advanced technology existed and then disappeared? Supposition?
Facts don't lie or have an agenda. Facts are just facts