Just look at the pyramids and the lack of solid explanation.
People have several ideas of how they could have been made. The problem is in finding out which it was. It is like an unsolved crime, we just don't have the evidence to show exactly how it happened, it isn't that we have no idea how it could have happened.
The best theory I have read is that they rolled the stones!
Yes, rolled them.
They essentially built 4 round quarters out of timber around the stones so that the stones where encased in a timber wheel.
Then they just roll the stone. When you get to the site, you dissemble the wheel and take it back to the quarry.
as few as 4 people could then move a few tonnes of rock.
Way easier than sleds sliding along sand or even over rolling logs.
Unfortunately papyrus does not last forever, and all historical accounts of their construction methods have been eaten by worms and mold, or decayed in fires.