One of the big wins we get from AWS is that you can do things like load structured data files (csv, parquet) from S3 directly in Redshift using SQL queries.
This is indeed pretty cool. They also have the `aws_s3` extension [1] for doing the same thing inside Postgres. Unfortunately, the extension isn't open source.
[1]: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_...