Posthog, Mixpanel etc are in the product analytics space.
They are designed to ingest up as many events as possible inside your product, eg user clicks, ab testing, backend events, etc.
After ingesting up events, they can tell you how many signups you had in the last month, what feature did your users use, etc.
Operational is built to track key events such as user signups, cancellations, etc. It can send you push notifications for these events and you can run triggers from these events.
This makes Operational great for understanding what specific paths a user took inside your product, setting up a audit logging system, triggering workflows manually, and solving other operational issues.
In other words, Operational runs complimentary to product analytics tools.