This showed up while searching on YouTube. I couldn't finish listening.

[Warpy]

9. Or it was more or less in a linear fashion

but the only place we've found the evidence is within the ruins of the city states that rose and fell within the last 7,000 years or so.

The real problem is what was committed to oral tradition like trade secrets. We're just starting to catch up there, the formula for unreinforced Roman concrete that outlasted even stone has finally been cracked. https://news.mit.edu/2023/roman-concrete-durability-lime-casts-0106 Likely a lot of the "aliens done it, I seen 'em" stuff will also be cracked, the trade secrets of talented builders.

Maybe the vid got better, but what I saw was outrageous speculation buy someone who didn't know what he was looking at and who hadn't kept up with experimental archaeology and paranoia about "they" who won't let science progress.

He might have a point about the latter, but progress it does, usually when evidence builds up enough, as in the case of the long term presence of syphilis in Europe before 1492.