Been thinking a bit about the future of hentai games with the addition of AI. I've tried CharacterAI, NovelAI, AIDungeon, and some other small projects, but they are far off in quality to ChatGPT or are filtered.
The AI developments are really cool, especially with chat bots. Unfortunately any half-decent one now is filtered, but who knows what another 10 years could bring. You could have conversations with a character that you have designed yourself and talk about anything you want. Maybe the script is set up with a premise behind the scenes, where a guy will turn up that will turn your relationship upside down, but beyond that it's all AI and random. Potentially endless replayability if you could tweak the premise and characters.
Long-term there's also AI video tech. Right now real-time AI rendering to video is very poor, but another 10 years? Not only could you be able to talk to that chat bot as if they were real, it could have a high-quality visual element. Full animated characters and places, etc.
And then there's AI voice tech too. That's already really good in a few cases and it just mainly needs refining in conveying emotion in voice tone a bit better.