Is that more a problem that your phone has crappy battery life? Mine charges whilst I'm asleep and lasts fine for the rest of the time. Also it fits in my pocket fine and is never inconvenient unless I want it to be (i.e. Turned off). You now have two things demanding your attention.
Also, what if you get a phone call when your phone is downstairs and you are upstairs?
Is having to pull your phone out of your pocket that bad? Do you even need to look at it unless it makes a loud noise at which point you can close to defer until later? Constant distraction is poisonous. On your arm, it's going to be worse.
Cookware has an established practical and has been with us in various forms for thousands of years so I think that's a poor analogy.
The pebble demands your attention. That is all. It does nothing that something else doesn't do already, costs a chunk of money, needs constant feeding and attention. At least a smartphone was a consolidation of communication and entertainment devices. This is a portable distraction. A poor one at that.
Do you think it's healthy to constantly stare at your heat rate, glucose level and blood pressure and micromanage every parameter of your life?
Also in a decade, you will pay a subscription fee for that data from the central provider that your watch talks to. That model is established already plus it will probably be linked to your health insurance profile as well by then. You'll wear one to keep your premium down...
I appreciate the goal but I'd rather we started with an IP-free core manufactured by multiple fabs and work up from there. The Chinese got somewhere with this by ripping off MIPS but I'm not sure that is the right solution.
Then there's the wireless stack and peripheral space which is even more complicated.
Edit: this was my intention when I went to university in the early 90's but I found sitting in front of a Sun workstation drawing squares (gates) very tedious.
If only Windows Phone had a greater market share. Despite being a UNIX guy I quite like it plus according to my colleagues (both of which are iOS and Android defectors respectively): You get to use a decent language (C#), Tooling is good and free, Apps are really scary fast, Unit testing is possible, One form factor, Approval is very fast and you can make money as the market isn't saturated to the point the SNR is against you.