AI pictures could be a good source of knowledge in terms of f.e. composition and use of color, but AI still messes up a lot of details or nuances about architecture, furniture and other details, as well as the consistency of lights and shadows, so I definitely don't recommend studying them directly.
If you want to learn creating beautiful anime / visual novel backgrounds, I recommend studying backgrounds of existing animes and visual novels (for me these were Nichijou and Clannad), as well as artists like しおん - https://www.pixiv.net/en/users/14707888 or _LM7_ - https://www.pixiv.net/en/users/420928
For the AI backgrounds in this post, I recommend to exclusively use them as a) draft backgrounds while developing a visual novel to then later replace with actual custom backgrounds; b) as finished assets in context that welcomes AI assets to be used, or c) as basis for rich thorough overpainting to take them as a sort of sketch and transform them into something that doesn't have any of the dumb AI artifacts and visual glitches and actually shows your own unique artstyle.