When parents asked kids to be home in my youth it was because we'd actually stay out for that long, as childhood was massively outdoors. Despite C64, Amiga, NES and the gang I remember a god lot of fun time outdoors alone and with friends. Summers were outdoors adventures of bicycling, fishing, hunting, picking berries in beer-infested deep forests. Long-distance skiing for fun during winter. We'd get sweaty and tired because we liked it.
Then came nerve disease and put an end to the outdoors hobby which I liked so much, preferred walking for 25 minutes over buying an expensive bus ticket for downtown. Doing the numbers for a few minutes with waking hours as "life" it's 30% and going down. If I lived in an area where there'd be no green of nature to see or birds to hear out of any window I'd get depressed.
Get outdoors while you still can. Take your kids out. Get the habit of walking for the fresh air, leave your phones and devices at home and just live.