Goes back to the part about known-unknowns vs unknown-unknowns. A refresher:
Observability is about having the ability to ask any question, explore or debug ANY system state, without shipping new code. Unknown-unknowns.
You're actively looking for ... well you don't know what, exactly. 🌝
It is not. (Good Lord, if you've ever tried to do exploratory interrogation using monitoring tools... like surgery with a butter knife) But it is *active*, not passive, and that can feel harder.
Or they just filling in the moat with the corpses of burnt out opsfolk.