Dreams.

The game can offer more than just pictures. There's so much else that rules can't cover. No one will buy a visual novel with static artwork, unless it's hentai. Maybe a couple of weirdos will.

I don't play visual novels, but as far as I know, hentai novels are the most popular and, therefore, bring in the most money for the developers.

Added 1 minute later

Well, development will end at the picture stage. No one will be able to afford the animation and code.

Theoretically, if you team up with a paid AI, something might work out. Or you could make a pixelated indie game that visually looks like Heroes II or Might and Magic IV-V.