there were less people back then.
less people means less likley for geniuses to come around.
less smart people to help control the flow of technology.
On a bell curve, approximately 2.5 percent of a population falls in the category of genius. 16 percent fall under very intelligent to genius. The population of ancient Egypt was about 2 million people. So that’s 32,000 extremely intelligent to genius people. That’s plenty to get some stuff done. And Egypt wasn’t some isolated wasteland. They had ports and traded and had political ties all over the Mediterranean and into Mesopotamia. So they also had connections to their brilliant people as well.
This wasn’t some bumbling people who suddenly built mega architecture. They had incredible intellects in mathematics, astronomy, the arts etc.