I'm in the somewhat rare situation of not being able to wear headphones even when I want to; the various concoctions I have to put on my ears eat through plastic like a dose of salts. Used to be I'd just listen to music, but now I get the full blast of whatever crap inconsiderate fuckwits think the rest of the world is dying to hear. The worst for me is whatever the genre of music is that sounds like some degenerate form of hip-hop as performed by an auto-tuned Steven Hawking accompanied by Demo #4 from a wheezy Bontempi. It's made even worse by the tinny phone speakers.
Even when I could wear them, I never got on with noise-cancelling headphones. Never really liked stuff covering my ears anyway, and they're far too isolating for me. Volume on my music was always low enough so I could hear what's happening around me. I don't really get how people function with them on.
Drives me fucking nuts, especially after a hard day when the journey home was a perfect opportunity to get out of work mode with a half hour for reading or doing the puzzles. Most of the time I'm able to ignore people's phones, but some are so loud or staccato they're just downright obnoxious. I've spoken up a few times when huffing didn't seem to have an impact; some people look sheepish and turn the volume down (or even off if I'm lucky), most ignore me completely, a few have gotten quite angry - saying if I'm unhappy with their choice of music, TikTok, endless adverts or even pornography on one occasion - then it's my fault for not wearing headphones. Sometimes other passengers chip in which I'm eternally thankful for.
I'd posit that the screech of brakes on the tube is fast becoming a thing of the past what with most rolling stock now having regenerative braking (i.e. no friction needed) but this hasn't done anything to reduce track noise - especially on the bendier bits. I think this is probably the largest cause of the screechings, and not something that can be easily fixed.
I'd disagree with those who say the tube is much quieter now post-pandemic, at least in my little patch of central. Frequently scrum-room only 7-10 in the morning and still busy all day with workers, students and tourists. Granted, the City and docklands seem far quieter now.