Davidovits’ theory is the only one that makes sense when you consider the alternative theories involve the prospect of carving limestone blocks the size of mobile homes with copper tools, floating them across a river, dragging them up to the construction site, lifting them high atop a pyramid, and having them fit withing a hair’s breadth.
Carrying baskets full of stone aggregate and dumping them into wooden forms seems more logical.
I will admit that the Ancient Aliens from Zotan theory is the most entertaining.
carving limestone blocks the size of mobile homes with copper tools,
Interestingly enough there is a lot of iron ore in Egypt; they used an iron tool in the Opening of the Mouth ceremony for the dead; W Budge also mentions a steel tool used in the same ceremony (Book of the Dead -1887) - this iron is assumed by Hawass & Lehrer to be meteoric iron.
Also any existing iron tools would have been seen as valuable, stolen, sold during any one of the Interregnums between the Kingdoms. Also the Arab muslims in the 7th century would also have stolen anything valuable like iron tools (for making knives and swords) leaving the copper and stone tools behind.
There is also a way to harden copper such that it is harder than steel.