I don't know your CS background but perhaps I do not view the terms "complex" and "tedious" the way you assume. A tedious parser is certainly tedious to write, but it is not (necessarily) complex. And from an engineering standpoint it is questionable that you lost all the formatting information from Word, which would have already demarcated what things were headers, code, and so forth. So, you had to use a roundabout way—an LLM—to recover that information from the semantics.
If what you're really arguing is that ChatGPT works well for language translation tesks, in this case translating mixed prose, code, and foreign languages--sure I guess that's great at productivity and removing tedium, but it's not that surprising a usage given what LLMs are. They are language translators.
In other words you're saying it's complex but your argument reduces a task that is straightforward but tedious for humans, to the problem complexity of natural language processing.