Anonymous wrote:What’s the social/emotional benefit of it?
Would you rather do it with cousins but they’re too far away?
Honest question: are you from the States? Because this was very common growing up in the Midwest. Almost every weekend. I do find them less so in this area in this day/age. I think that may be a combination of immigrants (anecdotally, kids of immigrants have been less likely to attend or host sleepovers, in our experience) and the overscheduled child (have to get up at Dark O Thirty for soccer games, etc.)
But to answer your question: they have them b/c they're fun. There are some negatives (sleep deprivation for a night) but, in general, the kids get a lot of bonding time together.