Most parents I know are deliberate about limiting screen time and ensuring their children don't substitute screen time for other activities. It's actually not that difficult to do so as kids are really good at finding entertainment in their environment even without electronics.
However, some parents give their kids all the tablet, TV, and phone time they want. As they grow up I can see them failing to learn how to play with others their own age because they'd rather reach for a screen than make an effort to do something. They can be frighteningly grumpy when separated from their electronic devices and can even throw tantrums until their parents cave in and give them more screen time.
FWIW, I've also watched parents reverse this trend by slowing weaning their kids off of screen time and substituting other entertaining activities. It doesn't take a whole lot to nudge people in the right direction, but putting that phone down and doing literally anything other than stare at a screen can be a difficult first step to take.