It will not come as a surprise that I do believe that you are on a passionate search
for knowledge and truth and accept that your mind is willing to absorb new information.
(Albeit you can be a bit dogmatic and determined, maybe even a little obstinate at times.)
I have no doubt that in the iron age (equipped with wheels, cranes and great roads), in particular the Roman era, they were very capable
of quarrying, transporting, and creating relatively fine finish on granite.
The process of quarrying such large columns is in the form of splitting the rock.
It appears that experts can even pick the "grain" to assist in the cleanest straightest alignment in which to split.
There is lots and lots of videos replicating this process . I can't recall which of them is the most convincing but it would be a good idea
if you watched some.
It is remarkable how straight they can make them. ( Thus reducing the amount of finishing work)
As for the finishing process, yes with an enormous amount of perspiration with iron/steel tools
and even (dare I admit) with hard stone pounders and abrasives a staggeringly precise finish is evidenced in the
most elite examples.
There are far too many sites around the world where in the last 2 millennia such activity is demonstrated with
a degree of documented history .
Not all of them could be recycled. Maybe some might have, but how would one ever have factual evidence
We in our respective countries are at a disadvantage to those that live or frequent Europe.
Most of (relatively new) Australian cities have the luxury of abundance of either sandstone or limestone.
But when I visit Melbourne CBD, near I hotel I usually choose, is a building once was a mid 19th C bank building.
Much to the chagrin and disgust of my lady, and bewildered onlooking pedestrians, I cannot walk past it without
glaring at and running my hands over the granite blocks beautifully finished that formed the foundationand lower levels of
the original building. Yes they had steam power etc etc.... but it really is just a more economical quicker way
of producing the result using steel.
As for copper/bronze age , no wheel , no crane, no roads, ancient Egyptians.... nah forget it!