the compression and general audio quality of the youtube stream. 

Wikipedia: The default video stream is encoded in the VP9 format with stereo Opus audio; if VP9/WebM is not supported in the browser/device or the browser's user agent reports Windows XP, then H.264/MPEG-4 AVC video with stereo AAC audio is used instead.

youtube transcodes uploads, people will generally find something random in whatever format, export it in their video editing software as aac at a low bitrate and then youtube will butcher it into their own bizzare formats for streaming.

Thinking about this, a lot of milenials wont have any idea about audio codecs, compressions and bitrates. 

These days people are consuming instantly whereas "back in the day", we all used to use services like "napster" etc etc and if you didnt already know (by ripping CDs etc), you soon figured out what bitrate, codecs and compressions were. 

Most people dont notice and dont care about audio quality . Never have and never will .
I would say audio via a laptop would never be 'good' quality .

For me, YT audio (played thorough decent speakers & amp ) is usually good enough for what it is .

Well back in the day an audio recording was an entertainment medium. Nowdays recorded music is a niche item with few people caring about it. Poor value for entertainment when compared to other entertainment media if you're buying it, and for streaming from spotify/tidal etc if one things not there or is a crap version of it, there is always something else to listen to.

Sure, you will get the odd tool fan saying that streaming is useless because their favourite artist isnt on it, but that is more a case of their favourite artist being a bunch of entitled jerks limiting access to their stuff.

Kids I know dont give a crap about music except for no copyright sounds, because in their minds, what is the point if I cant put this music on twitch or youtube. Its as good as useless to them.