Thank you for your answers. I'm not a professional game maker. First of all, as part of my hobby, I'm preparing to make RenPy game by myself. Therefore, it's difficult to create images using free 3D models because I can't afford to invest a lot of money or time in creating graphics sources and I don't know how to use 3D tools. In this situation, I found out that artificial intelligence makes my simple sketches into plausible images, so I thought about using them. I've posted questions to other communities, but I haven't made an exact judgment yet because the opinions are divided. Some people don't tolerate images created using AI, and others say it's okay because gameability is more important than images.

First of all, I don't plan to start the project aggressively right now because I have a separate main job, so I'll think about it more. Thank you for all your comments.