Indeed, though their video subtitles still appear within the player, and audio is simply like video minus the picture.
YouTube also has a transcript sidebar feature, where subtitles appear with time stamps in a sidebar, but for that purpose we already have TimedText pages where both the text and player appear. However, even on the TimedText page, the new player appears in a pop-up overlay that blocks scrolling, which prevents playing the audio and reading the transcript simultaneously. This makes the pop-up overlay appear like more trouble than it's worth.
I don't see how having the player in the layout would add significant complexity. It is the same interface, just not in a pop-up.
Thanks anyway.