Would a dongle be that bad?
Back in the Walkman days there was a dongle that acted as a remote control. It made it very easy to skip songs, change volume, etc.
Another improvement to this functionality would be a likely movement away from the current situation with non-standard signalling sent across the analogue connection. Right now you can get headphones with integrated remotes to pause/resume and control the volume, but the signals are not shared between android/iphone let alone desktop operating systems.