Why should readiness and liveness probes typically check different things?

Liveness should detect a fundamentally hung/deadlocked process that needs a hard restart; readiness should detect whether the Pod can currently serve traffic, which can be temporarily false (e.g., a downstream dependency is briefly unavailable) without the process itself being broken. Using the same check for both means a transient downstream issue — which should only cause Kubernetes to stop routing traffic to that Pod (readiness) — would instead trigger unnecessary Pod restarts (liveness), which doesn't fix the underlying dependency issue and adds restart churn on top of it.