Part of it’s obviously the changing social outlets and life situations as we get older, but IMO the biggest reason is that social interaction for its own sake l

Part of it’s obviously the changing social outlets and life situations as we get older, but IMO the biggest reason is that social interaction for its own sake loses a lot of its luster as people get older. Friendship becomes more focused and personal, alone time becomes much scarcer and more precious, and everyone’s just way less bored all the time. The threat of boredom is always a huge motivator for people to hang out and try not to be bored together. As people get older, that ceases to be a social motivator for many/most people. They may still have a bunch of other reasons for wanting to socialize, but boredom’s not one of them.