Anecdotally, I've tested this by having a network monitor traffic throughput and once a video is playing audio only, there is a noticeable drop in throughput which goes back up when you pull the video back up. Tested this a while ago so hopefully it's stayed like that.
Re:Moving from YouTube to PeerTube
by Majestic121 on Thursday August 20, 2020 @11:33AM
(#24224305)
I'm pretty sure Youtube music is audio only, but I can't tell for the actual Youtube app
On a different note, does anybody know if the stream is cut down to audio only when the screen is turned off? Or if there is anyway to get an audio-only stream? Streaming video when I'm off WiFi and I just want to listen to audio seems wasteful.