Comment by lmilcin

Just because you can do it with Postgres doesn't mean it is the best tool for the job.

Sometimes the restrictions placed on the user are as important. Kafka presents a specific interface to the user that causes users to build their applications in certain way.

While you can replicate almost all functionality of Kafka with Postgres (except for performance, but hardly anybody needs as much of it), we all know what we end up with when we set up Postgres and use it to integrate applications with each other.

If developers had discipline they could of course crate tables with appendable logs of data, marked with a partition, that consumers could process from with basically same guarantees as with Kafka.

But that is not how it works in reality.