I would expect all LLMs are going to be better at Rust than Zig - a strong, thorough compiler will simply prevent more mistakes, and the benefits of a "simple" language decreases the larger the code base gets. The more abstractions exist, the less valuable "no hidden control flow" or "no hidden allocations" from the standard library get, and that's before you add the mother of all abstractions of vibe coding.
I have no doubt that LLMs are good at Rust.
But I can’t reconcile the reasoning about “strong, thorough compiler” with the fact that LLMs are also fantastic at Ruby.
They also write really great posix shell (including very sophisticated scripts) and python.
Something more subtle is going on.