We know that the Inca didn't build Sacsayhuaman because they said that they didn't.
Anyone who has ever built anything can tell you that pounding stones don't explain this superb stonework. Not only is it an incredibly laborious process that you would stop after 20% of the effort for 80% of the result, but you can't achieve a fit like that after any amount of time if you don't have a comparably precise method of measuring the fit. Putting the stones next to each other and eyeballing it won't do.
Pounding stone seems reasonable to me. Obviously I don't have any proof or even strong evidence but I saw a video that changed my perception of what is possible. It showed two old men making a millstone with hand tools: https://www.youtube.com/watch?v=lscs5ZgNQrE. The amount of labour involved and quality of the finished item was astonishing to me. Maybe you'll think that the hideous amount of labour needed to make a simple geometric shape makes you even more convinced the Inca has some other way to achieve their even harder task. But it is a fun video anyway.
We know that the Inca didn't build Sacsayhuaman because they said that they didn't.
Anyone who has ever built anything can tell you that pounding stones don't explain this superb stonework. Not only is it an incredibly laborious process that you would stop after 20% of the effort for 80% of the result, but you can't achieve a fit like that after any amount of time if you don't have a comparably precise method of measuring the fit. Putting the stones next to each other and eyeballing it won't do.
Similarly astonishing to me is that Michelanglo's David was carved from a single piece of marble with a hammer and chisel. I mean, just look at it: https://en.wikipedia.org/wiki/David_(Michelangelo)
And the Inca inherited pre-existing structures.
The Inca did do stonework of their own, but not close to the standard exhibited in this article.