I do understand what you have been trying to convey regarding what the young generation deems critical nowadays… but I concur that an iPhone it’s not a necessity, maybe the telecommunications and internet, yes.
Back in my school days it was deemed a “necessity” having Jordan Nike Airs (or equivalent Rebook, LA Gear, Vans, etc), loose pants, funky head wear, etc… so much so that you would be seriously excluded socially if failing to follow the “necessary trend”.
But that doesn’t make it a necessity, what’s a necessity is having presentable reasonable clothing and shoe wear.
But sadly, mid-school never ended… today we exclude people depending on the type of fancy car they park on their driveway in front of their McMansion for others to see (instead of the garage because it’s parked full of useless trinkets instead), even if it is just rented out via leases. But still it isn’t a necessity, transportation is what is a necessity whether by a cheap car, bus, subway, bike.