for most people at the very low end of low income and low education group, this is a huge barrier.
Look: I haven been neighbours with people who had to search their whole appartment for a working simple pen to take a note - when asking for it they looked at me like an Alien: Really poor and uneducated people have high barriers in even the simpelst things.
Sure, phone choices in America are very limited compared to most of the world. But just go to walmart.com, seach for prepaid android and choose "New" condition. You'll see mainly entry level Motorola and Samsung offerings ranging from 40 to 200.
Well, I guess this means that they have successfully solved their smartphone availability problem. Otherwise, note taking tasks with a pen would be more important for them.