> Succinctness, functionality and popularity of the language are now much more important factors.

Not my experience at all. The most important factor is simplicity and clarity. If an LLM can find the pattern, it can replicate that pattern.

Language matters to the extent it encourages/forces clear patterns. Language with more examples, shorter tokens, popularity, etc - doesn't matter at all if the codebase is a mess.

Functional languages like Elixir make it very easy to build highly structured applications. Each fn takes in a thing and returns another. Side effects? What side effects? LLMs can follow this function composition pattern all day long. There's less complexity, objectively.

But take languages that are less disciplined. Throw in arbitrary side effects and hidden control flow and mutable state ... the LLM will fail to find an obviously correct pattern and guess wildly. In practice, this makes logical bugs much more likely. Millions of examples don't help if your codebase is a swamp. And languages without said discipline often end up in a swamp.