RDS is super expensive and while you're gaining traction and users you might as well use an EC2 instance.
ElasticBeanstalk seemed like an easy intro to AWS but it steered me into RDS. Of course I've abandoned the whole of ElasticBeanstalk for serverless development lately.
My first intro to AWS was ElasticBeanstalk and serverless seemed too daunting. But now I've been smitten and can't stop thinking serverless.