It's a form of networking.

If you focus on making friends instead of enemies (or at least people know they can rely on you, and are willing to say so to management), the word will get around, and in this disconnected environment, managers spend more time asking around about how other employees are doing.

Put another way - your reputation is a lot more important now than it used to be. It's a lot harder to schmooze the bosses than it was in person.