This seems to be a growing sentiment, perhaps in response to the enormity of modern smartphones. They're no longer a convenience but a payload.
Check out the variety of standalone smart watches coming out of China now, some even run full Android 5. I'm thinking of one which could act as a 3G-to-wifi hotspot for a tablet for when I do need to work on the go. That also gives much more flexibility in selecting a tablet without a SIM.
Continuously running the 3G/4G connection and sharing it over wifi would run down the batter pretty quickly. Watches need small batteries so they can fit on your wrist.
Check out the variety of standalone smart watches coming out of China now, some even run full Android 5. I'm thinking of one which could act as a 3G-to-wifi hotspot for a tablet for when I do need to work on the go. That also gives much more flexibility in selecting a tablet without a SIM.