Doc Reference: https://docs.redhat.com/en/documentation/red_hat_openshift_logging/6.3/html/installing_logging/installing-logging#install-loki-operator-cli_installing-logging 

By default, the retention config is not mentioned in standard installation YAML because of which end users use the exact same config for deployment and then object storage get flooded with a lot of logs. This breaks ODF and impacts the applications consuming storage from ODF.

It is required to add retention config in standard installation YAML in the documentation. If there is no retention, then the logs will not be remove / cleaned up from object storage until retention is configured or until lifecycle policy is configured on the object bucket.

Additional Point:

The YAML needs to be updated in both the sections (installation via CLI and web console)