I don't know if I agree.
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.
Most people don't like wire and don't care about genuinely good sound through wire vs. artificially sweetened (DSP-ed) sound through Bluetooth. That's what Apple is targeting at, the mass consumer.
Wired headphones are making a comeback though. They're even considered trendy/fashionable now.
https://www.cnn.com/world/wired-headphones-comeback-spc
https://mashable.com/article/wired-headphones-instagram-acco...
Honestly that "most people" seems to be more marketing driven than real opinion.
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.