unfortunately they will almost certainly get picked on. i dont think abstinence is the best idea here, better to educate them on the dangers and monitor/restrict what they are using the phone for. lest they hate you. but certainly for someone under 12-14 they do not need a phone.
as a side note, i think the way most people are introduced to the argument is by their parents when they are young. the parents are simply trying to get their children in the habit of considering others’ needs, while also saving their own money. especially since most of the time the kid actually is hungry, but just doesnt want to eat vegetables or whatever. if someone (irl) is arguing the starving people card to you as an adult when u are wasting food, then that is less reasonable: though they have good intentions, i agree it is not all that impactful on those hungry. but again, every bit counts.