If you are running a strong EDR platform, you're doing something right. EDR is essential. It's great at detecting and responding to malicious activity: suspicious processes, behaviors, lateral movement, and indicators of compromise.
But here's the uncomfortable truth: EDR does not tell you, with certainty, whether your systems are still in a known and trusted state. EDR tells you what it can observe from an endpoint telemetry perspective. It does not establish and enforce an authoritative baseline for your environment across files, configurations, identities, and infrastructure.