You get object storage with S3 but I'm not sure what else this SDK gets you. Not sure that's compelling enough for many pure front end developers.
From the article:
AWS DynamoDB: A NoSQL database service that allows scalability and many other features.
AWS.SNS: A Simple Notification Service that allows push notifications.
AWS.SQS: A Simple Queue Service that allows the creation and management of queues.
AWS.S3: The Simple Storage Service that allows object storage and management, one of the most used services.
AWS.STS: A Security Token Service that provides a temporary access token.