Wait, what is wrong with this?
I mean the model is the backdrop, these fashion companies aren't selling models, there selling clothes.
If you were already going to use Photoshop and stock photos the fill out the background, put the model on a beach, adjust the time of day, put other people into the photo, add sone palm trees, etc. The model (and indeed the entire original photo) is now a very small part of this the final product. If you could now just photograph your clothing on posed mannequins and fill in ai generated faces, what's so wrong about that? Why does the person wearing the clothes your selling matter more than the the people added from stock photos?