If you have 90-95% of everyone's needs (installing packages, compiling, putting files) covered in your DSL, and it has strong consistency and declarativeness, it's not that big of a problem if you need an escape hatch from time to time. Terraform, Puppet, Ansible, SaltStack show this pretty well, and the vast majority of them that isn't bash scripts is better and more maintainable than their equivalents in pure bash would be.
The problem is, ironically, that each DSL has its own execution platform, and is not designed for testability. Bash scripts may be hard to maintain, but at least you can write tests for them.
In Azure YAML I had an odd bug because I used succeeded() instead of not(failed()) as a condition. I had no way of testing the pipeline without executing it. And each DSL has its own special set of sharp edges.
At least Bash's common edges are well known.