Why do you think that? I think large format paintings might be in just as much danger.
There’s a large industry of talented artists in China, Vietnam, etc who copy famous artworks by hand for very low prices. They’re easily accessible online: you upload an image and provide some stylistic details and the artist does the hard work of turning the image into brush strokes. It’s not “automated” but I’ve already ordered one 4’x2’ AI generated painting in acrylic relief for less than the cost of a 1’x1’ from a local community gallery. I put in quite a bit of work inpainting the image to get what I want but it would have been completely impossible to get what I want even six months ago.
I’ve only ever purchased half a dozen artworks in my life and they were all under a few hundred bucks but with this new tech, it just doesn’t make sense to buy an artists’ original work unless it’s for charity. The AI can do the creative work the way I want and there are plenty of artists who are excellent at the mechanical translation (which still requires a lot of creativity, mind)