If I were to wear a watch, I'd like to be able to comfortably wear it while sleeping. I'd like it to record my vitals. I hear variation in sleep vitals is a pretty good way to detect illness early on.
Maybe it could vibrate at me when I snore, before it wakes my bed partner. Or vibrate to wake me in the morning, since I can apparently sleep though any noise. Hey maybe my bed could be one big charging mat!
But I don't like to wear a watch, so never mind.