What are some less untapped sub-genres you know?

I was playing cyberpunk 2077 and the blackwall popped this question in my mind. There can be this interesting genre of digital verse where a lot of interesting things are possible, like a mental jail for captives, or it can be used like a metaverse. Some anime already tap into it like playing an mmorpg.

Another one was dreams. Like your dreams become a reality, an apocalypse. To save everyone, you have to reacll what happened. Or when you sleep, you wake up as a different person, and return when you wake up.