As Romans would say: "Nihil novum sub solem".
This matter has been discussed for decades and there are no clear answers, neither in the orthodox field nor in the alternative field. We still don't know how could they build such an impressive monument. I don't buy the idea of an internal ramp, although it has interesting features, but it could be a good proposal, much better than the sigle huge ramp. All we have are hypotheses and speculations, because relevant evidence is poor or non existent. In any case this is a question for architects and engineers.
I think all of us would pay a great fortune to travel in a time-machine to the Old kingdom and see how the ancient Egyptians were able to do it... I said Old Kingdom? Mmm... exactly when? Or perhaps many centuries before...? ;-)
By the way, I miss so much the wise interventions of our companion Archae. Please, enlighten us soon with your irrefutable knowledge!