Imagine we wanted to make an exact copy of the pyramids in Egypt, the great pyramid specifically.
Never mind building them without machines. Do you think mankind, not just the current residents of Egypt, but do you think in this world there exists the technical know how and political will to even be able to do it?
There is no any building problem of the past that could not be resolved with enough slaves.
50,000 Nubian slaves won't get shit built without someone there with a plumb bob and the know how.
There is not much know how in pyramids. And I can't imagine what use of their technologies could be useful today for anything.
You know, tech of making wooden wheels for a wagon is pretty interesting and sophisticated (more than pyraminds, IMO), but who the fuck could need it today?
Same with pyramids. Humanity built a lot of things much bigger and sophisticated than pyramids. Take an average HPP dam f.e. or starting table of a cosmodrome. I could not think out not only why anybody will want to build a pyramid, but even if he want, why whould he use that ancient and ineffective tech?
I sometimes wonder if ancient civilizations realized that the poles shift and this shape could withstand the massive waves that might wipe out an area. Why are ocean fishing weights in a pyramid shape? Because they don't move easily in the tide
Ancient people was pretty competent, really. Especially in questions of protecting themselves from natural disasters. Othewise humanity wouldn't had survived.
However, pyramid shape is just simpliest to build and most stable shape possible. Most stable is tetraeder, but it is more complex to build - you have to do more math and use not only bricks with right angles. You could build pyramid of any size without any complex math. Easy to design, easy to calculate necessary material, easy to explain what to do to slaves. So, that pyramid shape.
Ancient people loved to follow KISS (Keep It Simple, Stupd!) principle. Meanwhile, this is a sign of high level of competence too.