Dogs obviously have incredibly more advanced olfactory systems but I feel like you're downplaying humans here. I'm pretty sure there's hundreds of very specific smells I could identify pretty well. Smell of home, pencil rubbers, chalk clouds, rotten bananas, denim.. things do have quite specific smells and there's a lot of things.
I think it’s pretty established that humans are very good with smell. We just aren’t very sensitive compared to dogs
Those are classes of things, not specific objects. We all know the smell of erasers, but can we identify the smell of a specific eraser? Part of it is sensitivity but it is also largely that our brains are not designed to associate smells with individual objects. Think of how we handle faces, which we can spot even if at a different orientation than we have seen before. Or how we can hear a specific voice amongst a crowd. Dogs do that with scent profiles.