Sorry, but I've been doing photography for so many years I can easily tell the difference. I don't care if you don't believe me though.
But yes, this is also about authenticity. There's a big difference between something that happened and something that didn't.
I think it's possible you may think you would be able to differentiate AI generated photos and real photos. But if you looked at that site and told me the SAME thing, then I would know that you actually are lying to me.