true, but why would anyone export it in an even more compressed format than what youtube offers? I don't do youtube rips so I don't speak from a place of experience.
okay, so, let me clarify how audio exporting works at the moment
you can choose 2 types of formats: Lossless, or Lossy.
If you choose Lossless (like FLAC or WAV) then you'll be left with the same quality that the YouTube video had, but at the cost of a huge filesize.
If you choose Lossy (like AAC or MP3) then, no matter what quality level you choose to export at, the audio quality will be degraded from that of the original, but you can minimize it to the point of not being able to hear it at the cost of a larger filesize.
But, if you just grab the audio stream directly then you get the "perfect" (equal to YouTube) quality at a pretty low filesize, since YouTube usually only uses 128kbps audio.