I do not think determinism of behaviour is the only thing that matters for evaluating the value of an abstraction - exposure to the output is also a consideration.

The behaviour of the = operator in Python is certainly deterministic and well-documented, but depending on context it can result in either a copy (2x memory consumption) or a pointer (+64bit memory consumption). Values that were previously pointers can also suddenly become copies following later permutation. Do you think this through every time you use =? The consequences of this can be significant (e.g. operating on a large file in memory); I have seen SWEs make errors in FastAPI multipart upload pipelines that have increased memory consumption by 2x, 3x, in this manner.

Meanwhile I can ask an LLM to generate me Rust code, and it is clearly obvious what impact the generated code has on memory consumption. If it is a reassignment (b = a) it will be a move, and future attempts to access the value of a would refuse to compile and be highlighted immediately in an IDE linter. If the LLM does b = &a, it is clearly borrowing, which has the size of a pointer (+64bits). If the LLM did b = a.clone(), I would clearly be able to see that we are duplicating this data structure in memory (2x consumption).

The LLM code certainly is non-deterministic; it will be different depending on the questions I asked (unlike a compiler). However, in this particular example, the chosen output format/language (Rust) directly exposes me to the underlying behaviour in a way that is both lower-level than Python (what I might choose to write quick code myself) yet also much, much more interpretable as a human than, say, a binary that GCC produces. I think this has significant value.