You might be giving the watch too much credit, it relies on the phone its paired to for almost everything.
It's tightly integrated into the OS and it really is just an extension of the phone with health tracking, apps run on the watch but all the data is pushed to it from your phone. All the health data it collects is pushed back to the phone and makes most sense when viewed from the phone app. The only input method is Siri voice commands, there is no app store or anything like that, that is all side loaded from the phone app.
LTE is only really any good for making or receiving phone calls, iMessage via Siri, maps (directions) and streaming music. It isn't designed to be a phone replacement, on LTE it only lasts about 3 hours doing a workout (GPS+LTE), 7 hours in standby, 1 hour phone call, 4-5 hours streaming music. When synced to the phone on Bluetooth it lasts 2-3 days.
Think of it as a really advanced fit bit that can make phone calls when away from its iPhone master but relies upon its iPhone master for almost everything else.
