Following are some of the use cases where Kafka is not suitable :

Kafka is designed to manage large amounts of data. Traditional messaging systems would be more appropriate if only a small number of messages need to be processed every day.

Although Kafka includes a streaming API, it is insufficient for executing data transformations. For ETL (extract, transform, load) jobs, Kafka should be avoided.

There are superior options, such as RabbitMQ, for scenarios when a simple task queue is required.

If long-term storage is necessary, Kafka is not a good choice. It simply allows you to save data for a specific retention period and no longer.