If you did implement it yourself, you might have spotted a critical point that might simplify the whole thing...
This is the "Jodie Foster in Contact listening for the SETI signal with headphones" theory of how production software systems work.
And yet, continuing your analogy, she made an amazing discovery this way.
There have been multiple points in my career where I framed a problem as simple in my head, and it mostly was.
But then, one small detail changed everything. And it wasn't something I'd have thought of until I was writing the code.
I shudder thinking about the number of these issues hiding in LLM-generated code.