Rust’s compile times are crippling and its type system is easily one of the most rigid of all type systems (lifetimes are part of the type!). The latter is one of Rust’s main selling points because it allows encoding business rules into affine types, but that’s very very far from flexible especially when compared to Typescript (or Python or Haskell and their many ways of polymorphism). Traits add an orthogonal axis of flexibility but they’re still limited by lifetimes (see async_trait and generic associated types and specialization).

“Flexible” means the range from gradual typing (‘any’) to Turing complete conditional types that can do stuff like string parsing (for better or for worse). Structural typing vs instanceof and so on.

There’s really no comparison between Typescript’s type system and Rust’s. It’s worth noting though that Typescript is a bolted on typesystem that has explicitly traded soundness for flexibility. That’s the real tradeoff between Rust and TS IMHO. Rust is sound and expressive but not flexible, while Typescript is expressive and flexible but not sound.