Now Kafka has ZK taken out and tiered storage coming in these factors are becoming mute points. With tiered storage Kafka has 2 layers and hence the benefits of

Now Kafka has ZK taken out and tiered storage coming in these factors are becoming mute points. With tiered storage Kafka has 2 layers and hence the benefits of broker/storage decoupling. By comparison, Pulsar has broker, bookkeeper, S3, and ZK layers to contend with. This is why a second layer was never added to Kafka directly.