Wow, what a load of junk science.
The Great Pyramid dates to around 2570 BCE. We know that from ancient writings. We know that from archaeological records. We know that from carbon dating items from the tomb itself. There is no debate over that, other than the nutcases that want to believe aliens built it or some such nonsense.
But yes, the "Giza Complex" is indeed older, because there were already things constructed there before the pyramids. But anything of that era is long gone, not unlike the original Spanish pueblos and Indian settlements where Los Angeles now sits. But what is there now only dates to around 2500 BCE.
And what all that has to do with Toba, I have absolutely no idea. That however is very real, and we know of the near extinction event because of DNA studies.
But yes, humans 75 kya were almost the same as modern humans. We even know that was true of humans 5 kya because we have studied them.
But we also because of Egypt know what humans were capable of doing when. Because they left behind a lot of not only structures but written records so we know what they were capable of and when. A century before the Forth Dynasty and the Great Pyramid, we had the Third Dynasty. Who built the first pyramids like the Step Pyramid.
And prior to that, Egypt was just not building any monolithic structures.