I shut it off on mine because I have a personal phone and a work phone (both apple) and anytime I have the two near each other it goes off with that insanely annoying bell.
As for the child protection issue, I thought Content and Privacy restrictions allowed parents to block adding new contacts on their kids phones or does this override it? That to me is the simplest solution.
They’ll probably just double/triple the price of new parts now if you want to use them.