There are some other categories like Food & Drink [0], Just Chatting [1] (everything from talkshows and outdoor over scams (Elon Musk is apparently giving crypto away currently) and softcore porn), or Music [2].
Outside sometimes watching a new RPG, I stay away from gaming sections as the community tends to be toxic and turnbased RPGs are a smaller niche anyway.
[0]: https://www.twitch.tv/directory/game/Food%20%26%20Drink
Out of curiosity, as someone who never used Twitch, what is the discovery process here? As in how did you find this specific streamer in the first place? My (likely biased) impression was that the platform is mostly for gaming streams.