I love these GGG threads because I read statements like that and marvel at human ingenuity. When I was teaching, I ran across a very consistent bias in my teenage students that people who live in other countries in vastly different cultures, or people who lived in ages past are inherently less intelligent than "we" are. Yet they, as is the case with many adults, cannot do simple arithmetic without the use of their calculators. Give them four sticks and some string and they would be unable to devise a way to stake out a geometrically square foundation on the ground. I could, and I could probably survey out a fairly straight 'Roman road'. But I know I couldn't build a pyramid or an Incan wall or make a likeness of someone out of stone. So props to those who did and whose works have stood the eons - they put our modern world in perspective.
It's gotten a little better recently, but I remember about 20 years ago when most children couldn't tell time on anything other than a digital clock and small children couldn't tie their shoes because of velcro.
We rely on computers for everything today, but the mathematical equations for the atomic bomb, jet aircraft and much of the space program was done with slide rulers. As you pointed out, we have the most advanced engineering programs imaginable today, yet nobody has been able to produce a reasonable theory of how the pyramids were constructed.