Looks more like reliability vs speed. Small & fast compilers skimp out on various safety checks and edge cases. Yeah it might mean segfaults and crashes in weird archs and situations, but it's fast on perfect machines.
Rust’s cargo check appears to be quite fast, and afaik offers no less safety checks than a complete build. Of course, I’ve never verified, but there’s a clear and substantial allocation of time spent compiling rust, after all the safety checks.
