Because in some cases, adding a style prompt gives almost the original image: https://www.reddit.com/r/StableDiffusion/comments/wby0ob/it_...

And yet nobody has managed to demonstrate reconstruction of a large enough section of a work that is still under copyright to prove the point.

The only thing so far discovered is either a) older public domain works nearly fully reproduced b) small fragments of newer works or c) "likenesses"

That’s the key question of the lawsuit IMO!