It actually works, but you still have to disable it to see how far into the video you’ve gotten. The J, K and L keys still work for pausing and cueing, at least.

If you allow us to still see the audio controls, this would be perfect. Also, to only enable it for a single tab/page rather than have it apply to every tab. Also, a more detailed description on how this is better than the others (most extensions and userscripts only hide the video and set the quality to 144p ever since july 2024, when youtube started merging both video and audio sources. I assume this extension manages to somehow still block the video and only send the audio which saves bandwidth and makes it load faster)