Some parents. Elite schools in Manhattan and Palo Alto send home fliers that parents (or at least those I know) read.
Screen time of all types is monitored. And the children have a somewhat hilarious self-protecting pride in their control over digital intake. (Most of them. Thinking of two brothers, one who eats his veggies because he, and I quote, doesn’t like his poop going soft, and self moderates cartoon watching and phone fucking around. The other who steals my phone to watch loud videos.)