@chainq There's definitely a mismatch of values, and Rust is future-looking rather than backwards-looking.
Rust is 10 years past 1.0 release. The implementation is quite mature in what it targets.
Lack of obscure/legacy things is immaturity only if you assume having them is a goal, but Rust prioritized other things, like safe multithreading, early WASM support, modules, error handling, metaprogramming, UB prevention/detection. From Rust's perspective these are woefully immature hacks in C.