Humans are obviously unique in an interesting way. People only "move the goalpost" because it's not an interesting question that humans can do some great stuff, the interesting question is where the boundary is. (Whether against animals or AI).
Some example goals which makes human trivially superior (in terms of intelligence): invention of nuclear bomb/plants, theory of relativity, etc.
But that's unique in the sense of "you have a bag of ten apples and I have a bag of eleven apples, therefore my bag is unique". It's not qualitatively different intelligence than a dog's, you just have more of it.