Comment by Groxx

There's also fuzzy datatype mapping in general, where they're like 90%+ identical but the remaining fields need minor special handling.

Building a generator capable of handling all variations you might need is extremely hard[1], and it still won't be good enough. An LLM will both get it almost perfect almost every time, and likely reuses your existing utility funcs. It can save you from typing out hundreds of lines, and it's pretty easy to verify and fix the things it got wrong. It's the exact sort of slightly-custom-pattern-detecting-and-following that they're good at.

1: Probably impossible, for practical purposes. It almost certainly makes an API larger than the Moon, which you won't be able to fully know or quickly figure out what you need to use due to the sheer size.