People have worked with stone for 100s of 1000s of years, including some possible small images of animals and such; one apparent stylized statue of a human dates back 400K years. Stone was used to work stone at this site. But it appears you’re really just objecting to the writing in the article.
I object to things stated as fact rather then stated as opinion or quantified with the statement that with our current level of knowledge this is what we believe.
And yes I understand that this was written by a travel writer rather then a scientist but my objection stands.