In an open-plan office, "turning their chair around to chat" involves everyone in the vicinity who overhears the conversation, and "turning around" is only possible for the single-digit number of next-seat neighbours.

Consider the opposite extreme of private offices. An impromptu meeting involves some walking, but otherwise the meeting stays between just those directly-involved. There's no cost to anyone else.

Keeping this distracting effect in mind, silent communication (messaging) looks more attractive.