I’m wary of putting kids in front of screens, more so handheld devices.
Your kids? Or other people’s kids?
I was speaking, prospectively, of my own, on the view it isn’t healthy for kids in general.
Depends on the kid and the amount and the content.
I wager there are those kids who don’t fare worse in cognitive studies, I intend to play it safe as I can.
I doubt very seriously that any kids are worse off for their time in front of the TV.