Anything beyond that and LLMs require a lot of hand holding, and frequently regress to boot
If you write a prompt with perfect specificity as to what you want done, an agent like "Github Copilot+Claude" can work at about the same level as a senior dev. I do it all day long. It writes complex SQL, complex algorithms, etc.
Saying it only does boilerplate well reminds me of my mother who was brainwashed by a PBS TV show into thinking LLMs can only finish sentences they've seen before and cannot reason thru things.
Even if my prompt was ambiguous, the LLM has no excuse producing code that does not type-check, or crashes in an obvious way when run. The ambiguity should affect what the code tries to do, not it's basic quality.
And your use of totalizing adjectives like "zero ambiguity" and "perfect specificity" tells me your arguments are somewhat suspect. There's nothing like "zero" and "perfect" as far as architecturing and implementing code goes.