Why are there no newer clip-on headphones?

I was amazed by the KSC75 as long as it worked. I feel like the clip-on solution is one of the most consistent way to provide sound. It is reliably at a given distance from your ears and does not tire them like most headphones do eventually. You literally forget it is on your head. It does not rely on pushing up to your ears, akin to a higher-end earspeaker. You can hear yourself speaking without any change whatsoever.

I will buy a Koss headphone again. But I hope the clip-on headphones will eventually get some kind of reemergance.

Why is it that we are not getting newer ones?