My experience with Rust is that it tries to squeeze every last drop of performance, but instead of relying on simplicity (C) or unsafety (C++, the reason Mozilla started it was to reduce C++ memory-related bugs), it introduces language complexity (lifetimes, "prove that your code is safe, or fallback to a runtime overhead such as Mutex") and a little-bit of runtime overhead (explicit Option<T>/enum checks). In my mind, it doesn't play in the same league as high(er)-level garbage collected languages. It was made for robust low-level applications, which is why it's being considered for the Linux kernel, and not Lisp.

Concatenating strings in a GC language is easy, you just "+" them together, the cleanup will happen eventually. Concatenating in low-level languages means you have to think about the memory allocation(s) taking place, and the format("{}{}") is a lot more powerful for anything more than just adding two strings. What if you want to prepend "https://"? In GC languages, this might be an extra string being allocated and discarded, in Rust, it's a constant hard-coded into the binary. It just happens that the language has attracted a lot of people who are used to higher-level abstractions due to it's relatively pleasant syntax, type system and abstractions, ecosystem and perfomance.