You have a url that purports to be a certificate of authenticity. What happens to that certificate of authenticity when the site goes down, or gets sold to someone who decides to replace all the images there with poop emojis?
I don't like NFTs personally (wasteful, scam-ridden, investor bro culture), but if you compare them to how art has worked for the past century (or more) it's not so different. If you own a Banksy the certificate of authenticity is far more valuable than the actual artwork, which is easily reproduced. It's all kind of silly.