So much this. After having encountered ADTs for the first time in Haskell and later on in Rust and other languages, any language without sum types (like Rust's enums) feels wholly incomplete. And the destructuring pattern matching is the cherry on top.

ADT and pattern matching really does it. Older languages certainly have their pull and can do a lot but with many modern coders having an interest or even education in higher level mathematics, easily being able to do that will put you way ahead of the competition. Even the hyper-pure Haskell now runs its own ecosystem and has actual systems written in it.