Kafka replaced ZooKeeper with Kafka itself already a few years ago https://cwiki.apache.org/confluence/display/KAFKA/KIP-500%3A...

And first announced to be "production ready" in October 2022.

(WarpStream founder) WarpStream has a completely different architecture than Kafka: https://docs.warpstream.com/warpstream/background-informatio...

That said it does require a lot of metadata to orchestrate all the different concurrent operations over S3. We handle this with a custom metadata store that we run in our cloud control plane.