that first article finds only one issue with Kafka-for-ES: limited number of partitions. Use pulsar, problem solved? Doesn't have the support or ecosystem of Kafka, but surely more than eventstoreDB.
- Lacking support for key-based look-ups: when trying to materialize the current state of an entity, you cannot query Kafka efficiently for just those events (a partition-per-entity strategy doesn't scale due to the partion number limitation, which may change with KRaft in the future)
- Lacking support for (optimistic) locking: you cannot make sure to reject events based on outdated state, unless you apply work-arounds like a single writer architecture
Like a table, there can be an arbitrary number of rows (>millions), thus you could have millions of event streams. You can't have millions of Kafka partitions. The scope/scale of a Kafka partition is not designed for that small granularity.
Again, I have no issue with Kafka and I think Pulsar is superior in the event streaming/platform space. I also the Kafka ecosystem is impressive and I love listening Confluent Cloud podcast! But it is not designed for this use case.