One word: "Courage"
People who moved to bluetooth got arguably worse sound quality.
For wired headphones, there were very few lightning headphones and they mostly sucked.
Now with usb-c you can get a broader range of headphones (because other phones have gone with usb-c).
either kind needs a dac inside the dongle, or the shell of the headphone, or have a bulky external dac.
3.5mm is still king for decent wired headphones/earbuds.
https://www.cnn.com/world/wired-headphones-comeback-spc
https://mashable.com/article/wired-headphones-instagram-acco...
When you simply can't purchase one thing, then you move to the next thing.
I have several wired and wireless headphones, all for different uses, and the existence of wireless headphones don't make the wired ones less useful for their particular strenghts.
All my three phones have a headphone jack.
I don't have or plan to have an iPhone.