Zuck’s thesis is going to be vindicated in a few months and he will end up being basically spot on in terms of ubiquity in 10 years. The pivot to catch up conceptually with Apple is going to be tough but doable.
I can't understand why you wouldn't want to be able to wear a perfectly normal pair of glasses that have the additional feature that you can pull up your phone screen at any moment without actually getting it out of your pocket.
The key insight is that the device will be off most of the time.