also the audio output of each computer is routed thru the box as well, so i can mix my girlfriend’s computer into her headphones as well as my microphone, so she can hear me with noise canceling headphones, or turn off my microphone if i’m working so she can do stuff without my mic in her ears.

Or if she’s watching a movie or something I can also add her computer audio to my headphones. There’s even a separate audio output for host 1 where you can put ‘chat’ on, like discord on a dedicated interface, so that your application audio is clear and isolated. It’s hella expensive but it really is a great device

Or maybe there's two people in the room, each on different channels altogether. In this case the other person is just uncorrelated background noise instead of a persistent echo.

Or, in-context: There's two people in the same room, both talking on the same Discord channel.

Anyway, audio routing is useful. Being able to route audio with two different PCs is a pretty neat feature of the rodecaster.