This is more of a general question With the availability of free languages such as Rust, Clojure, F#, Go, Typescript, Idris, Raku You have a solid option that cover ever possible paradigm and style of programming you may fathom

Why would any one invest time or effort in a commercial language such as Ada,

(1) Ada isn’t a commercial language

(2) What other free language covers the style and paradigm Ada addresses? Rust maybe (I haven't really done a detailed analysis) now subsumes Ada, but has a different focus and a lot of cognitive overhead related to that focus. Haskell or another static functional language with a robust type system might provide an alternative approach to some similar benefits, but not the same style and paradigm.