Honestly, if you care about longevity, Rust simply isn't the language yet. I'd at least wait until there's a specification and a GCC frontend.
Anyway, C does have some benefits as a programming language.
• "Legacy" projects like Linux and CPython will keep it alive for decades to come.
• It's extremely portable. Rust is less portable, and even when Rust supports a niche platform, it's relatively clunky to get things started.
• C libraries are always very easy to call from other languages. Rust isn't quite there yet, and translating things like traits can be a bit of a pain.
Anyway, C does have some benefits as a programming language.
• "Legacy" projects like Linux and CPython will keep it alive for decades to come.
• It's extremely portable. Rust is less portable, and even when Rust supports a niche platform, it's relatively clunky to get things started.
• C libraries are always very easy to call from other languages. Rust isn't quite there yet, and translating things like traits can be a bit of a pain.