To paraphrase sherlock holmes, when you eliminate the impossible, whatever you're left with, however improbable, must be the truth. Even when you account for beasts of burden, movingmulti-tonne boulders of rock was far beyond the capabilities of ancient people given what they had available to them at the time (and, like I said, it is beyond even our modern capabilities). If it was impossible for humans, or humans with animal or machine assistance, then it must have been aliens because this is the only possible explanation. The technologies available at the time were pretty basic, they had the wheel, which would be useful for stuff like carriages, pulleys...etc, Certainly such things would have been useful for transporting smaller blocks to a building site for something like basic house, but that's just not the case with the pyramids.
Just out of interest, how do you think that ancient people with basic technology built the pyramids? How do you account for such heavy masses having to be moved against gravity? Even when you take account of animal assistance (horses, camels or possibly elephants?) it would not be enough power.