The measurement framework your team built was optimised for confidence. I want to ask you whether that was the right objective.
Reporting systems evolve over time to produce outputs the room will accept. Metrics that tell a coherent story. Numbers that move in the right direction. Dashboards that smooth the signal rather than amplify it. None of that is dishonest. It is the natural adaptation of a measurement system to the social environment it operates inside.
The problem is that a system optimised for confidence will continue to produce confident outputs even when the commercial reality underneath it is deteriorating. It is built to smooth and it smooths the signals a genuinely governed system would be acting on. The conversion trend that is down slightly for three quarters running gets averaged into a flat line. The cohort that is performing badly gets blended into the aggregate. The channel that has been losing incrementality for six months keeps its budget because the attribution model was not built to show incrementality.
You know the difference between a dashboard that shows you what is happening and one that shows you what you need to show the board. The gap between those two things is where your commercial risk is building.
Related reading