I don't follow your analogy at all. Suppose I want to build an application with xyz features. My research yields that there are no such applications that include xyz features. However, there are plenty of applications that might have x feature, y feature or z feature, or a combination of two, but not all three.

If there are no such applications, I don't have a choice but to write it myself. This could take some time, especially if an MVP is all I'm interested in. LLMs are a novel tool in building an MVP. If time is a constraint, I can use an LLM, which should excel since xyz features are in its training set.

I suppose your analogy follows for developers who write applications that support abc features even though there are already applications out there that support abc features. Yes, I don't think that is very interesting. Your umpteenth clone of Snake is not interesting.