The moat
Switching costs of a deployed agent, network effects in threat telemetry, and brand with security teams (dented, not destroyed). Microsoft is the giant in the room.
Pain, risk, or retraining required to leave.
The product gets better as more people use it.
Patents, data, licenses, process knowledge, regulation.
Fixed costs spread over a volume rivals cannot match.
Structural ability to be the low-cost producer.
Pricing power from trust, habit, or identity.