Wearables are not all smartwatches.
Wearables are, currently, not very good at input. Not just me, but anyone who writes about their serious love of anything (mostly smartwatches) says the game changer is near-ambient notifications.
Also: gathering general info, such as fitness trackers. But that's sensor extension, not deliberate user input.
Future tech is full of wearables http://www.technovelgy.com/ct/SrchRes.asp and there are already (mostly experimental or very, very specialized) smart clothes.