So, you want to carry something around in your hands. That’s fine.
Are you thinking that there is some rule about your input device? If you want a smart phone in your hands there is no reason (for you) to limit yourself.
There will be amazing input devices beyond strictly the glasses, however, including input options in the glasses themselves brings the potential for simplicity.
To type something like this I am using both hands, my head is down and I have stopped productively doing the other tasks that surround me.
In other words, in a hands on productive work environment I am severely handicapped using only my smart phone.
If most of the work I do requires only the glasses, when on the rare occasion I have to type something out (rather than dictate it) I can pull out the old smart phone, if that is what I am comfortable with.
I feel surprisingly alarmed at the lack of incite many people have. It is a bit like the beginning of air travel and the resistance that occurred then.
I am certain that Direct AR will be tremendous, and hand held input devices will “accessorize”.