"The sky" has nothing to do with it.
The watch lives on the wrist. It's more convenient -- you don't have to hold it in your hand -- but it's less versatile, too, because you can't aim it easily, nor can you use it very well after setting it down somewhere besides your wrist.
When we FaceTime with my dad, he usually puts his phone on the table and props it up against a book. He can't do that with a watch if it's on his wrist; and if he were able to take off the watch and still video chat with it, it'd too small to be worth looking at.
You can "do all sorts of crap" from today's smartwatches already, in case you haven't noticed. You can change the lights in your house, set schedule reminders, create and check off grocery lists, read the news, screen your emails, check local weather radar, play little games, log your sleep patterns.... oh yeah, and MAKE PHONE CALLS.
(seriously: before you post again, you need to sit there with your forearm at face height for ten minutes as if you were having a video chat conversation on your watch. Do it. Then tell us how great you think it'll be to do for real.)