Please. Software piracy is also widely considered stealing even when no physical object is removed. If you're going to posture about "better arguments" you should consider not wasting time with pointless semantics.
Prompting generated 'art' is NOT creative; you are just doing a pattern search which contains ZERO expression on your part, again akin to googling images and picking one of the results, then claiming it's 'your work'. And no, typing search keywords is NOT expressive. Also no, a little 'in-painting' to re-roll your search doesn't change that either.
Only someone who doesn't understand anything about creativity would compare machine pattern extraction with humans learning from and being influenced by other art. They're not even remotely similar. People talking like these glorified search engines are one step away from "advanced AI" are fully delusional.
Any responsible lawyer will tell you commercial use of derivative AI generated images based on copyrighted work that you do not have license to use is copyright infringement. For this same reason, Valve recently announced they are not accepting game submissions that contain AI-generated material for which the developers cannot demonstrate they have full rights to use 100% of the material involved, which if you're relying on any of the popular image generators you cannot because they're ALL built on stolen work, which you have no rights to whatsoever. The only legally acceptable way to use generative AI commercially is if you train it from scratch exclusively on data you have the rights to use, so either your own work, or properly licensed or public domain material.