So i was wondering if itch.io is used for publishing games that are semi- photorealistic etc. or is it mainly for publishing those "Lower Quality" games?
I don't think "triple-A" means what you think it means. That said, the best way to answer your question is probably to look. Does Empires and Tribes, for instance, meet your bar? It was easy to find under first-person 3D games.
AAA just means the game has spent lots of money. There is no real meaning behind it because gaming company made up that term: https://en.wikipedia.org/wiki/AAA_(video_game_industry)
just like how "blockbuster" doesn't always mean a good movie.