Key Control Indicators (KCIs) are essential to measuring the effectiveness and performance of security controls. Without them:
The organization cannot assess if controls are working as intended
It's difficult to demonstrate due diligence
Risks may go unnoticed
While other answers point to operational concerns, the complete absence of KCIs presents a critical governance gap that compromises the organization's ability to monitor and manage control health.
"KCIs provide actionable metrics that support proactive control management and are fundamental to governance and assurance."
- CISM Review Manual 15th Edition, Chapter 1: Governance Metrics and Reporting*