Every Way to Get Structured Output from LLMs

The baml config files look a lot like code. For example in baml:

    class Resume {
        name string
        education Education[] @description("Extract in the same order listed")
        skills string[] @description("Only include programming languages")
    }

Could be expressed in Python like this:

    class Resume:
        name: str
        education: List[Education] # Extract in the same order listed
        skills: List[str] # Only include programming languages

Two benefits I see are that it would make the file leaner (because Python is nicely lean) and provide free parsing and syntax highlighting.

Is there a benefit of rolling your own DSL?