For production environment, the features of container level log is obviously not enough. Usually, we need a logging system to collection, pipeline, query, analysis logs. Viewing the log aggregated at the entire cluster level is a common requirement. KALM provide a simple solution out of the box called logging system.
EFK (Elasticsearch) and PLG (Loki) are the most popular logging system of the moment. They have their own advantages. Kalm plans to support them both.