I was playing an eroge and my first thought on seeing the in-game art was "this sort of looks AI generated". I passed it off as the developer just having one of those art styles until I literally saw NovelAI and some other AI tool in the credits. That WOULD explain why the CGs had no variants.
You know, if you're going to make me pay money for something you generated instead of made yourself, first of all don't fucking do that shit, but at least use something other than NovelAI.