I upvoted both you and the OP, for making good, honest observations.

And for relating stories about thoughtful, controversial engagements with art. Because that's kind of the point of art.

The Mona Lisa isn't "art" anymore; it was once, and now it's a pretty artifact with a lot of historical significance. But that's not art.

Art is the kind of thing that makes educated people say, in public, "that's not art". And, thus, by its existence and the reception to its existence, true art makes our conversations about art richer, more emotional, and (over time) more precise. And once all of the nuances of this conversation are exhausted, we need new art.

Which is why the Mona Lisa isn't art. At least not anymore.

And if you disagree with that, then we need to have a deep conversation about art, and history, over the course of which both of us will have hopefully learned new things about both art and history.

Art is a recursive question, not an engineering problem.

Edit: I should point out that this comment is intentionally recursive.