Applications with features for user stories.
AWS CLI is a very useful tool, because it can do simple things with AWS. In order to do more complex things, usually you have to "script" multiple commands together or write a Boto script in Python. But if the tool just came with those complex things already pre-designed as a feature, we wouldn't have to script it, it would be more reliable, easier, simpler, and nobody would need to bang their head against a DSL to get the functionality.
Nearly everyone on AWS who has wanted to try Fargate could use the following function: "Build me an ECS cluster, create everything I need for it (a VPC, security groups, etc), create an ECR registry, upload this Docker container to the registry, create me a Fargate service with tasks for the thing I uploaded to ECR, create one ALB for the cluster, add target group forwarding rules for each Fargate service in the cluster, and manage everything in Route53, including domain and certs".
Now, you could spend hours/days trying to set up Terraform or Ansible to do all of that, or script it with Bash or Python in a few hours. Or you could run something like "aws ecs user-story fargate-apps --cluster-name foo --service-container docker-image:latest --service-name some-img-name:latest --service-url https://my.custom.domain/some-img-name/ ". No DSL. No plugins. No cobbling together 100 lego pieces and reading 200 pages of documentation. No scripting. It's a very common user story, and the AWS CLI already has literally all of the functionality you would need.
But that won't happen, because the IT industry is purposely designed to be unnecessarily inefficient, complex, and expensive. If a tool like AWS CLI or Terraform just bundled this user story natively without you having to "compose" it like a DSL, the companies that produce them wouldn't make as much money, and could potentially incur more cost through the maintenance of it. An open-source community could support it, but it'd mostly be written by engineers of private companies, and companies are pathologically terrified of releasing any intellectual property without lawyers and contracts and CLAs and so on.
Literally half of the reason my job exists at all is that nobody has yet bothered to release the cobbled-together lego components of an enterprise organization under the public domain.