Well, the survivors write it, from their viewpoint, to suit their ends. I think it is highly possible that civilization advances in waves, and that the high points may or may not be preserved in the inevitable cataclysms which also occur, possibly as a result of the hubris of the learned.
We may have forgotten more than we know.
To a degree perhaps - I too am a catastrophist. But more to the point, history is levered to fit the current model (and has been before). And as long as evolution is embraced, and science stands opposed to God, aspects of history will continue to be ignored or de-emphasized to, as I said, fit the current model.
When in fact, history stands against them. They are speaking lies (at least of omission). Things like the OP, ooparts, ancient cyclopean architecture, and etc. all fly in the face of what is being taught as true.
And that goes all the way back.