Point taken :)

In the car they are used as a hands free kit. My car radio can be used to do calls as well but the headphones, only in one ear while driving, do have much better call quality

How is that less safe then playing the car's stereo? I have one in my ear at a reasonable volume when driving with others so they don't have to listen to my Geeky podcast or music.

Many of them also act as partial earplugs, and block out more external sound.