Expose your kids to activities that are more compelling than screens. Trust me, once you take a kid go-karting, they aren't going to be as excited playing a video game.
Do cool shit with your kids. Go skiing, camping, fishing, go-karting, flying (small plane tours), drone racing, etc.
I know most of us here are nerds, but the jocks really do have life figured out when it comes to fun stuff.
I realise HN has a disproportionate amount of software engineers, but I know my parents would struggle to afford the likes of skiing, flying, go-karting as regular activities, never mind in sufficient quantities to displace video games and the internet. Even a trip to the bowling alley was a rare treat when I was growing up.
Inexpensive outdoor activities like biking, skateboarding, ball sports, etc, all accomplish the same thing. In purchasing supplies for these activities, you're essentially signing them up for something that will consume their time and energy, leaving little to expend on diving into internet rabbit holes.
It takes a few years before even something as simple as a walk to the park isn't exciting anymore. And I think the thing that's implied in most of the pessimistic responses here is "you have to start early or you lose control".
Do cool shit with your kids. Go skiing, camping, fishing, go-karting, flying (small plane tours), drone racing, etc.
I know most of us here are nerds, but the jocks really do have life figured out when it comes to fun stuff.