Improve Bitrate + HDR + 120FPS/Higher Resolution
Higher Bitrate: (Above 10.000, with video quality selector can be managed so if someone won't use that high download usage, he can tweak it), we still have a really low bitrate, and that force us try to tweak OBS to reach higher quality with lower CPU encoding speed. Still this is not a miracle, and 6000 bitrate is so limited (even if there is a trick to go beyond and reach 8000 bitrate).
HDR: OBS doesn't support because it's not worth it nowadays since Twitch is not supporting it, but other platforms are starting to give a hint to this technology. I think would be nice to have this option since Twitch is being used in so many Smart TV's in the present. So they could enjoy Twitch in a higher quality. Probably this option should need Twitch partnering with OBS or any other streaming program to make it possible in the best way.
Higher framerate/resolution: These days we're having better connections that allow us to go beyond the old limits, we could make this work since right now is really normal to see a gameplay in 120FPS and even the next gen consoles are supporting it.
Twitch is the best stream platform, but our technical options are the same since almost 10 years ago. We should aim to higher quality so there are no quality loss between our viewership and our content.
It's time to wake up and make some improvements :)
Now that OBS 28 officially supports HDR, I hope HDR support will be examined on Twitch.