I am childfree but a lot of my close friends have kids now, and this is a huge topic of conversation for all of them. Working out how much time they spend on devices, what they do on the devices, etc. They don't want to segregate their kids from learning important technologies at a young age, but neither do they want their kids to be online 24/7. I honestly don't envy the situation.
I think these restrictions are honestly a pretty good baseline guideline.