Firestore has better SLO than Confluent's own managed Kafka offering (5 nines [1] vs 4 nines [2]).

If you use it as a system component and not a do everything backend it is the most production ready clientside technologies on the planet.

[1] https://docs.confluent.io/cloud/current/clusters/cluster-typ...

[2] https://cloud.google.com/firestore/sla