That's assuming I ever use only one pair of headphones and don't need connecting to aux cables / external speakers.

Or that my headphones are always used with just iPhones.

Basically, no more plug-and-play. This is exactly why 3.5mm was good: universal plug-and-play.

Naw, not if I want to get to work and then hook them up to my computer. Or I want to connect my phone to my car via an aux cable.