> for the longevity of the device....

I doubt it's really baking itself; most devices have a lower temperature target set in the software/firmware so that the user doesn't burn their lap, but the default thermal management behavior is done completely on-die.

I always wonder whether the heat calculations are correct. For example, if you compute the equilibrium temperature in a room on a table, then you get a cooler temp than when sitting on a lap that is 98.6 F. If the temperature sensor is near the CPU (i.e. one boundary of the heat equation solution), then it might not see more than a degree or two difference in very different external environments.

It sure can't, which is why I'm not doing it anymore :-) For typical development setup (+ some music not from YouTube) it stays gently warm though (while macOS is stone-cold).

FWIW you can use mpv to play just the audio from any site supported by youtube-dl or yt-dlp (so youtube/twitch/a hundred other platforms):

  $ mpv --no-video https://www.youtube.com/watch?v=xxxxxxxx

or maybe even something like this:

https://wiki.archlinux.org/title/Mpv#youtube-dl_audio_with_s...

I've been using a variation on this theme for years, don't even really know how YouTube looks these days

It's not so bad. You can burn yourself on a metal plate that is at 45 degrees. This temperature is manageable by the electronics inside.