It is useful. It serves a number of purposes. Gossip is an enormous way of exchanging information and thereby of exchanging power. There is power in telling something you know or think you know. It bonds both teller and listener together with a sense of sharing something slightly forbidden.
People crave news.
Houses in early New England were built close to the road so that passersby might give the latest. And a little gossip makes it even more so. People are now used to news that also entertains. Let me tell you a story. Everything is grist for history's mill, even, or perhaps especially, gossip.