Was at dinner with my partner's family. His sister acquiesced to his niece when she demanded her phone 5 seconds after finishing her meal, and said nothing while the girl sat there watching loud videos. Nothing about 'hey we're in a restaurant' or anything about being polite and making conversation. She's 13. Has no concept of boredom or how to act around adults. Because there's zero requirement to.

I think it's fine in moderation and when it's some manually curated service like the children's section of streaming platforms (but even then it's not perfect considering Cocomelon exists), or in the case of YouTube you're watching it WITH your kid to avoid running into anything weird (though I think any platform meant for content aimed towards children should be 100% manually curated). The problem is when it's excessive or it winds up sending your five year old down a bizarre rabbithole of pregnant Spiderman twerking videos because you didn't bother to moderate what they were watching.

You got some good answers but remember too, you're only seeing a fragment of those kids at your place. The screen might for example be a special rare reward for them to keep them quite so your friends can visit you... doesn't mean they're on scree s all the time.

My kids aren't particularly screen born most of the time, but when we're out I often relax the rules to keep things smooth. The fact that it's a rare treat makes it even more effective