It's rare that a company needs something like Kafka.
Kafka introduces a number of issues related to the development of client code and data stores (if any) and the maintenance of these things. It's important that the actual scale justifies the expense incurred.
It's not rare, using Kafka in place of a prober db is crazy though. There are tones of use cases that benefit from having Kafka a very common one is putting Kafka in front of the data processing pipeline to absorb spikes without data loss.
It's rare that a company has spikes of that sort that can't be handled in far more mundane ways. Most companies do not operate at a scale that merits this sort of solution.
Look at the engineering blogs on LinkedIn for the reasoning behind creating it. It's over-kill for most use cases.
It's rare that a company needs something like Kafka.
Kafka introduces a number of issues related to the development of client code and data stores (if any) and the maintenance of these things. It's important that the actual scale justifies the expense incurred.