Of course there's more to it but someone taking a picture of the Mona Lisa with their smartphone doesn't add much to it and certainly doesn't commend the same respect as Da Vinci painting it in the first place.
I see what you're getting at, but in your analogy, Leonardo da Vinci (the creative and intellectual driver of the overall work) maps to the black-box LLM behind an API, where the boilerplate web app wrapper maps to the Mona Lisa's constituent oil paints, and perhaps also the backing poplar panel and frame. In other words, wrapping an LLM is like updating the frame around the Mona Lisa.