Lol, cloudformartion historically did't support really huge and mandatory parts of aws resources and resource parameters and as there was no Roadmap of support until previous year https://github.com/aws-cloudformation/aws-cloudformation-cov... it was not fan because basically you couldn't even try for example to enable RDS storage autoscaller for RDS via CF template. That's why terraform was created because of AWS CF didn't support own AWS resources.