Paintings aren't painted by humans, they're painted by paint brushes. Therefor, they are not art.

That statement is ridiculous on the surface, but humans have always used tools and machines to produce art, which have gotten more and more sophisticated over time. No matter what machine is used, there's still a human designing the thing.

There's no magical cutoff where you can say "This was not produced by a human". It's just that the degree of indirection has increased over time.