You have opened a big can of worms that was explored a century ago, if I throw a bucket of paint on a canvas and let it drip, is it made by people? I could argue that the entire painting was made by gravity, which is definitely not human. Where do you draw the line? Is it art if the work is completely digital and made with digital tools, what if I use smart brushes? A camera?
Humans have consciousness, and free will which is expressed through intention which forms a causal chain. Photography on its own is usually vapid but it’s subject can be meaningful.
I don’t know who you’re quoting. Art is made by people, it’s literally in the definition of the word art. Google it. You haven’t disproven it by observing gravity. Idk what to tell you.
Your statement isn’t complicated but it’s also not logical or accurate. If art is what is perceived by people then everything is art and art is a redundant term for everything.