Yeah, I found this weird. Maybe it's some over-obsessive American thing? Random, no-reason sleepovers, or BBQ-style sunday gatherings, and other "just get together and eat so children can play" activities are fairly common among parents with small kids.
It's certainly not like I remember it in the 80s, but still happens a lot, and my uninformed take is: "community" in the US was never that cohesive, it only took so much to make it fall apart.
It is by no means exclusive to America.
Community in the US was largely centered around the church. I think it is an uphill battle getting a large group of people to get together and hang out multiple times a week when they don’t have a very compelling reason outside of the socialization itself to do so (i.e. the threat of eternal damnation)