Recording is not streaming
The recording is separate from the broadcast. You can record at full quality while streaming at a lower one, and you can record without streaming at all.
A great many people use this purely as a recorder. That is a legitimate way to use it.
Crash-safe segments
The recording is written in segments that stay playable. If the machine fails mid-event you lose the tail, not the file.
Pausing
You can hold the recording and resume it. The gap is cut out of the file rather than left in it, so a break does not become twenty minutes of an empty room.
Isolated recording
Turn on isolated recording and every camera writes its own file alongside the programme — up to twelve. Every microphone can write its own track, up to thirty-two.
This is what turns a live event into editable material. Without it you have one mixed file and no way to fix a bad cut.
Replay and clips
Instant replay jumps back and rolls it again, at speed or in slow motion.
Mark a clip while the event is running and it is exported afterwards, landscape and vertical. Marking as it happens is far easier than finding it later.
Trimming
The trim tool joins the segments into one clean file and cuts the dead air off each end. For most events that is the entire post-production job.