Linux screensharing needs to be fixed.

It has been a known problem since streaming for linux launched, that you cannot select one of your screens in a multi-monitor setup. As an example, if someone who has two 1920x1080 monitors arranged horizontally, would have a total resolution of 3840x1080, and because of discord's inability to differentiate monitors, that ridiculously wide video would be compressed into 720p for a non-nitro user, which is virtually unusable.
Besides, there's no way to stream audio. Linux users are forced to work around this issue by emulating webcams and mixing the output from ALSA or pulseaudio and real mic to a software mic.
tl;dr: Screensharing in linux just barely works enough to be listed as a feature, but it's not nearly as useful as it could.