my mother’s old fashioned response seems to match up with the research. when we sat in front of the TV too long, she’d yell at us and make us stay outside playing the yard.
it’s interesting you both report the lack of sports involvement (and i’m assuming they may not even have gym class as some schools don’t?)
the decrease in physical exercise correlates with increase in distraction. maybe make them earn their screen time with exercise or phsyical activities or even put them on a treadmill to access their tablets