Not everybody is using their headphones on the go. 99% of my headphone use is at my desk while I work. Wired is more convenient than wireless since it's one less lithium battery to charge.

It's true that humans are not particularly sensitive to audio quality, but they are very sensitive to audio latency. If all you do is listen to buffered audio sources then latency is not important but the moment you need to use your headphones in an input loop then wired is the superior technology as it offers close to zero variance in latency.

Wireless is convenience on the go and when you don't give a shit, like work calls.

Wired is for when you want to listen to music you really like and it's too late to use the speakers.

You can have low quality, low cost and very portable wired headphones, as well.

You can also go for moderately priced cans and just feel your ears tingling the first time you listen to something through them.