I have no doubt the watch is capable of being completely independent. I think the main concern here is battery life. How would it do with LTE/5G connection with a 1 bar (poor) signal?
Apple is certainly capable of putting all those cellular antenna, a built-in SIM, and anything else needed to be used independently inside the watch.
Apple is certainly capable of putting all those cellular antenna, a built-in SIM, and anything else needed to be used independently inside the watch.