It really matters what you mean by “dead.”

Are wired headphones disappearing from the “mainstream consumer” market. Yes. Most people, when given the choice between buying AirPods or a wired headphone/iem for a similar price, would pick the AirPods 9 times out of 10.

But are we going to see wired headphones being completely phased out. Not yet. Most hifi headphones are still wired, and the hifi market isn’t going anywhere (it’s growing if anything else).

I my opinion, wired headphones are being replaced in the mainstream consumer space, but the market for wired headphones is still there.