At that time, LLMs weren't as proficient in coding as they are today. Nowadays, the decorator approach might even go further and not just wrap LLM calls but also write Python code based on the description in the Docstring.
This would incentivize writing unambiguous DocStrings, and guarantee (if the LLMs don't hallucinate) consistency between code and documentation.
It would bring us closer to the world that Jensen Huang described, i.e., natural language becoming a programming language.