Doesn't seem to hurt twitch - The twitch UI looks like a toddler was given free rein with all the crayons.
Once you view a stream the only things you see are the video player, details about the streamer, and chat.
Not sure what you imagine could be better, but if you want to know what really bad UI looks like, check out Mixer.
Floatplane has made a very conscious decision not to influence the user's decisions on consuming content; there's no algorithm, recommended videos, or trending page. you just have access to the videos of people you want to support.