Earlier quoted context omitted.
{Hypothesis, test, loop} is the scientific method, and I can guarantee it is being used when fine tuning an LLM.
...but in a technical context, not in a scientific one. One thing is identifying (age of copper; age of bronze) the best ways of smelting ore to obtain the metal through trial and error, another is to try and understand the nature of materials.
That is to say, the two things you mention are the same process. "Identifying the best ways of smelting ore to obtain the metal through trial and error" is the easy part, when you get to pick low-hanging fruits in a field. But as the easy options get cleared out, continuing improvements requires increasingly complex, sophisticated methods - that's where the process transitions towards "trying and understanding the nature of materials". It's still the same process, but couple layers of abstraction up from the original "how to get better stick than neighbor and beat them instead of getting beaten".