has anyone actually answered this yet?
the pyramids at giza were built by peasant farmers, under the supervision of government experts on astrology and engineering, etc. It was state funded at all levels and surplus grain made food a non-issue.
The thing about ancient Egypt is the nile. "Egypt is the gift of the Nile," is a quote historians use to convey it's importance. The nile is a rare type of river for many reasons, for one it moves so slow you can go up and down it by boat, sail to go up (south) and minimal rowing if you want to go back (north) with the current--making it the best highway in the classical world. The other thing it did was predictably, and gently, flood. Like seriously abnormally consistent behavior for even the most predictable of rivers. annual, gentle flood = great harvests = more people = even more grain = even more wealth and population growth. nice feedback loop huh?
so what do you do when you're wealthy as god, and the people actually think you are god, and there are 100k of them, but all their farms are under water right now, and you need a tomb to ensure your nice afterlife, AND not just any tomb but you wanna be as grandiose as possible to project power, leave a legacy, and also as your house in the hereafter, and the peasants are pretty well motivated cause they think this is for their god.
so when you put all that together, over some decades, you get the pyramids, the only world wonder to enjoy the honor in antiquity and contemporarily.
Now as to how it was actually built... this was a long time ago since i was taught this but in antiquity there was a Cypress (hard wood) forest approximately where Gaza is today, maybe even closer. you can sail the timber right up to where the construction is going on. I don't know where the stones came from, but if not mined VERY nearby they'd have been shipped in too, then rolled on the logs (by both elephants and men) to construction site. from there the pyramid is being built in layers, like an onion. inside out and bottom up. each layer is built stair step style, with as many as 20 men using levers to lift these individual carved stones inches at a time. obviously this is backbreaking work with high mortality rates.
so this is the overview of how it is done. i've left a lot out cuz i can't remeber. the one thing that is very interesting is that the pyramids have hardly settled at all, despite their enormous weight. That part actually is a mystery AFAIK. Maybe they did get some alien help.