There is evidence to suggest that our cave–dwelling ancestors polished many of their flints to a degree far surpassin...

Emil-Kunkin on December 25 at 08:14PM

We don't know this, but we don't need to. If if we're true that hunting were not the only purpose for flints, then it is possible that those other purposes required more polishing than hunting did. This undermines the idea that it must have been art, perhaps the additional polishing was for other practical reasons.