I don't have figures for YT, but Spotify taps out at 128kbps, so I imagine YT is no better and likely worse. But, as you say, the 'kids' probably don't care as they listen through earbuds, laptop/tablet speakers or Beats (which are godawful, and essentially a scam).
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Quiver Search for FATALISTS on Spotify, Amazon, Apple, &c, Sun 15 Aug 2021, 21:03,
Reply)
www.google.com/amp/s/thenextweb.com/news/how-to-stream-spotify-at-the-best-possible-quality/amp
(, Mon 16 Aug 2021, 10:07, Reply)