ETL vs ELT

[rahulverma]

Thanks for explaining ETL vs ELT.
I have a quick query, Why would one do a complete extract and load at first, and then transform the data, and then load it again to consume it for reporting? I see three storage phase here, DB1 from where extraction happens. DB2 where its directly loaded/dumped, after transformation, DB3 where transformed data is stored.
I see ETL makes better sense where we extract what is required, transform the data as per the business rules and finally load to final Target table.
Why would one go with ELT over ETL?