Ada has held its own in the safety critical space for just over 4 decades. Over the last 10 years Rust has pushed into the same space with varying success. Among other features, most notably Rust is missing the powerful declarations and convenience of use of subtypes. In this talk at the FOSDEM 2025 Ada Developer Room I went into the various features that make Ada so useful for ensuring the absence of bugs, and where Rust stands on each of these features.
Oli Scherer (Mon,) studied this question.