the law is there because parents are fucking clueless unprincipled whining crybabies, who need a lot of support, and sometimes that includes a bit of pushing ...
or who knows what problem is this supposed to fix. orphans buying phones? kids buying secret phones behind their parents back?
I frequently see comments which would have made sense in the past (e.g. early 2000th) but kinda aren't fully reflecting reality anymore
it's as if humans have a tendency to make up their mind/world view in their younger years and then tend to kinda stick with it/only change it slowly as long as no big live changing events happen
Once you get outside the SV and NYC bubbles, the vast majority of kids do not have their own laptops in the US. Phones, obviously are somewhat more common, but as even you note that's mainly with regard to teenagers - the average 10 year old in middle America does not have their own phone.