It feels on a par with illiteracy. The motives and circumstances are different, but it's got a similar level of assumption. It's kinda rare and requires significant adaptation, so it's just way easier to assume it doesn't happen.
I don't think that a law to help people get smartphones is the answer, the way we made literacy education mandatory. But it's rapidly going to be seen as a handicap.
I don't think a skill is the same as a leased possession
Literacy is something the state funds for you to acquire and that can't simply be taken away
A smartphone is something you need to acquire and manage yourself, and it furthermore needs to comply with the rules set by an overseas corporation: you can choose between Apple or Google services but neither of them needs to take you as a customer while they're gatekeeping access to certain government and most transportation services
Literacy skills increase monotonically though. If you learn to read adult novels while in grade school, you can still continue reading grade school books as well. Whereas if you learn tech to the proficiency of understanding how corporate apps are attacking you, or if you simply take administrative control of that computer you carry everywhere, then you can then find yourself unable to engage despite having higher than the basic skill level.
I don't think that a law to help people get smartphones is the answer, the way we made literacy education mandatory. But it's rapidly going to be seen as a handicap.