The surprising bit is that 10% of Americans DO NOT own a smartphone. That must be exceedingly difficult. Increasingly everyday activities require them, without fallbacks. I presume those numbers exclude children, and then if you account for the infirm, it wouldn't surprise me if we started to get to universal levels of ownership.
It's people over 65. Cell phone ownership is pretty much universal, but only 78% of people 65+ own a smartphone. I don't think that's really surprising at all. I wouldn't expect an 80 year old to adopt a smartphone when their cognition, fine motor control, and/or vision is going. And who needs one in a nursing home? I bet if they broke it down further you'd find that the non-ownership skews towards people who were already elderly ~15 years ago.
