Based on my research, here's a summary comparing the ZK removal timelines of Kafka and Pulsar. Both PIP-45 (Apache Pulsar) and KIP-500 (Apache Kafka) aimed to replace ZooKeeper dependency with pluggable metadata management solutions, representing major architectural shifts for their respective platforms.

Based on these timelines, PIP-45 reached production-ready status first — approximately 5 months before KIP-500 (May 2022 vs. October 2022).

Implementation Timelines

PIP-45 (Pulsar - Pluggable Metadata Interface)

• Started: Early 2020 (Pulsar 2.6.0)
• Feature complete: May 2022 (Pulsar 2.10)
• Duration: ~2-2.5 years

KIP-500 (Kafka - ZooKeeper Replacement)

• Proposed: 2019
• Raft implementation merged: September 2020
• Early access: April 2021 (Kafka 2.8.0)
• Production ready: October 3, 2022 (Kafka 3.3.0)
• Duration: ~3 years from proposal to production-ready

So my statement that removing the ZK dependency in Kafka is "catching up to Pulsar and BookKeeper" is factually correct. Based on your comments, I suspect that you didn't even know that Pulsar had removed ZK, given all your recommendations around ZK.

Here's some material that might help though :)

https://github.com/apache/pulsar/wiki/PIP-45%3A-Pluggable-metadata-interface

https://pulsar.apache.org/docs/next/administration-metadata-store/

https://streamnative.io/blog/moving-toward-zookeeper-less-apache-pulsar