I'm fine with you or anyone else being impressed with this, but for many others like me this isn't impressive at all. I believe anyone can produce drawings and paintings like these; even much younger kids, once you teach them this very simple grid method.
You say art is a subjective discussion and I agree. What we don't seem to agree on is what art is. Perfectly copying a photo by using a grid certainly isn't art to me. Or course, if he took any of those photos, then yes, we could subjectively discuss if he's a good artist or not, but his realistic drawings have nothing to do with that.