How did prior civilizations grow them if we can’t?
There is only one conceivable response, as Vulcanian Spock would say: they did have some levitation technology. The ancients had two techniques for raising such large stones, according to what I’ve learned during many years of research on the subject.
The first approach was to employ sound-based technologies.
Sound is basically vibration, and you can levitate anything by enveloping it in a very precise sound of a very particular frequency.
The brain’s power provides the basis for the other method. Have you noticed the skulls that are elongated? I think they possess telepathic talents as well as the capacity to levitate items as a result.