Exactly. Each stone put on top of each other would likely need at least four cranes to lift and put exactly into place, all the way to the top. That would be extremely expensive in terms of fuel, machine wear-and-tear, etc... Modern skyscrapers are more compatible to be built with modern tech rather than ancient structures. How could a people with more primitive tools be able to accomplish that if it's that difficult.
The answer is they had a more compatible technology to do those types of things, likely from the Nephilim, who also built similar structures in Peru. The Peru folklore was there were giants in the land that enslaved the human masses and eventually resorted to canabalism (ie eating the our "inferior human species" to them) when the land did not produce enough food from the human slaves to feed them, and they were very violent. They were wiped away from a flood. That narrative also checks out with other flood stories, and especially the Biblical account (ie Genesis 6 - the giants in the land, the book of Enoch), which portray an elder race comingled with women, produced an offspring of giants which wrecked havoc in the land. The elder race (ie fallen angels), made an exchange with the people at that time for technology (ie the types used to build the Pyramids), in exchange for wedding their daughters, and then the Nephilim were born.
It's likely this elder race had other bases elsewhere too, and a war had occurred in the distant past which made Venus and Mars uninhabitable and created the asteroid belt from another planet which was obliterated in the conflict. The Earth belonged to the humans, and their only claim to the last planet was to comingle and wed with the humans to create a hybrid offspring and try to salvage their reign over the last remaining planet in the system. What started as a benevolant technological exchange ended up in so much trouble that a flood was necessary in order to restore order to this planet, and re-insert humans as the domianat species.
However, there is a new threat. The Greys have a secret hybrid program where they are trying to replace humans in a stealth way, by abducting them and creating an army of hybrid human-grey aliens, abducting cows and extracting their blood to augment DNA, and the elder race will likely take advantage of them, and defeat them in a future UFO war (maybe not too much in the future as you are seeing all the disclosures from congress), and try to reinsert themselves like they did in the past in Genesis 6.
Concepts of this is found in Tim Alberinos's book, Birthright, which I purchased on Amazon. This guy has some really serious deep stuff.