The leader and follower nodes serve the purpose of load balancing in Kafka. As we know that leader does the actual writing/reading of data in a given partition while follower systems do the same in passive mode. This ensures data gets replicated across different nodes. In case of any failure due to any reasoning system, software upgrade data remains available. If the leader system goes down for any reason then follower system which was working in the passive mode now becomes a leader and ensure data remains available to external system irrespective of any internal outage. The load balancer does the same thing, it distributes loads across multiple systems in caseload gets increased. In the same way,   balances load by replicating messages on different systems and when the leader system goes down, the other follower system becomes the leader and ensure data is available to subscribers system.