I saw this phenomenon of people withdrawing inwardly years ago, before the wireless earphones were even a thing (at the height of the iPod)

I do not see this anywhere but cities, which are congested with noises from traffic, trains, airplanes, etc., as well as human noise, people bustling through corridors and talking on buses/trains etc. and I noticed that I wear my wired earbuds and play music into them from my phone out of habit, whenever I board a bus, just because there's always people talking more loudly to their seat mates than they need to.

If it wasn't for that, I wouldn't wear them. For context, I'm a single woman over 50 who works from home (self employed in tech, as well as sort of an urban homesteader) and rarely need to go anywhere farther than someplace I can walk to, as I live in a very walkable area.