The only thing which enables reliable use of LLMs are statistical techniques.

Even the most constrained and well-designed Disney world ride will break down in some embarrassing way every now and again. As you increase the # of parallel rides, the chances that at least one of them will touch the desired parts of the search space go up dramatically.

The fact that the major model providers keep publishing nano/mini/luna variants should be a massive hint that there's more to this than one big fat loop magically one-shotting everything.