How do RevOps teams catch issues before they start affecting revenue?

I’m researching a problem RevOps teams face revenue leakage which I’ve talked with other orgs and they report they didn’t even know they had it.

Anyway, when Something breaks in the revenue stack, but no one notices right away. Pipeline data may become inaccurate, billing may stop matching the CRM, etc.
Dashboards and alerts often show the impact only after the issue has been happening for some time. Then someone has to trace the root cause across Salesforce or HubSpot, billing, the warehouse, product systems, and other tools.

Soo…

1. How do you catch these problems today?
2. How long do they typically go unnoticed?
3. How do you identify and fix the root cause?
4. Have they caused meaningful losses through revenue leakage, delayed deals, incorrect billing, inaccurate reporting, or wasted team time?

I’m trying to understand whether teams continuously monitor for these issues or mostly rely on dashboards, alerts, and someone eventually noticing that something looks wrong.