I just find voice control too outward to use in public. I don't want people to know what I'm doing, even if it's something totally innocent, plus it would also be super annoying to be on a train full of people going "blah blah blah" to their devices.

If we could subvocalise with throat or other microphones/bone speaker then maaaybe, but I feel like it's better left to a brain interface and we should really just stick to touchscreen/typing interaction for now.