She advocates for prohibiting the use of phones with internet capabilities to those under 16, and states that the best parental control is, precisely, the parents
Yeah, that's the thing, those apps don't really give kids the sort of privacy we enjoyed as kids. It's probably better to limit access to safe apps or something like that, depending on age.
How many parents do you imagine are going to actually do this? Free time is a resource most parents rarely have. It's the reason a smartphone ends up in a child's hands: to keep them occupied.