256k mp3 using youtube-dl. Works for me. To me 192k is borderline, 96k is very low. Prefer high quality lame vbr encoded, but I'll take what I can get :-)
Youtubes's best available audio is usually either 128kbps AAC-LC or 160kbps Opus -- both these codecs usually sound substantially better than MP3, and at these bitrates should be "transparent" with most material, (aside from whatever other processing YouTube does, or what was done before it was uploaded to them).
Converting this to MP3 means a lossy-to-lossy transcode which can only cause further deterioration, and increasing the bitrate to 256kbps (or anything else) isn't going to fix that -- at best you won't be able to notice any audible difference, apart from having larger files for no benefit.
Unless you need MP3 files for compatibility, instead of using the -x option to extract audio and converting to MP3, you'd probably be better off just using -f with the best audio format, and perhaps re-muxing in to a different container if required.
`youtube-dl` downloads from many more sites than just YouTube. As for the quality, people listening to streaming music probably tend to not pay much attention to that. As indicated by the popularity of music uploads on YouTube.
Well, higher quality audio is feasible to stream from a technical perspective. It's just that YouTube does not prioritize that. They likely care more about video experience.
So I would bet that any major audio-oriented streaming service beats YouTube on quality.
I tend to think as YouTube as more useful for discovery. At that, it is very good. If I decide I like something I will listen to it elsewhere with better quality.
Youtube in HD modes often has AAC at 192 kbps. Bandcamp, which I'd guess is a music-oriented service, for non-bought tracks seems to give me mp3 at 128 kbps. So yeah, sounds like Youtube is quite alright for discovery until you're ready to part with the money (though Bandcamp is much lighter on the cpu overall).
However, this whole discussion falls firmly under ‘suum cuique’, and quite pointless in the light of `youtube-dl` being not just for Youtube, as already mentioned.
