The weakness of Rust WRT LLMs is compilation times. LLMs code faster and hence spend relatively more time waiting for compilation than humans do, so on reasonably sized projects (e.g. 100k+ lines) Rust's ~10x slower compilation starts showing up as a bottleneck. If you're writing some critical infrastructure it makes sense to pay that cost, but if you're writing some internal service that's not publicly exposed to the internet then development velocity may be a bigger concern. (I'd argue that slow compilation also influences human development velocity, but for some reason developers very rarely try to quantify this.)

10x slower is like an extra second, if that, for compilation times for the sizes of changes an agent like codex makes.