The idea is that each of these roles ‘Loader’,’Transformer’ for example will be assumed by specific service accounts that will do specific functionality. For example: ‘Loader’ will be used by a ‘Data Ingestion’ tool like Fivetran to ingest data only. ‘Transformer’ will be used by a ‘Data Pipeline Transformation’ process, for example, stored procedures or DBT models or Dataflow models.

Hence the segregation.