Why is docker stats not a substitute for a real monitoring stack?

docker stats gives a live, point-in-time snapshot of CPU/memory/network/IO usage in the terminal, useful for quick ad hoc debugging, but it has no history, no alerting, no dashboards, and stops the moment you close the terminal. Production monitoring requires persistent storage of metrics over time (Prometheus's TSDB) plus visualization and alerting (Grafana) to detect trends and notify on anomalies.