Because the TypeScript runtime is not a web app? What part of my statement did not connect?

Likewise, the reason for the Copilot SDK to move to Rust is that it compiles to native binaries with no runtime and the FFI can interface with all of the supported SDK languages cleanly. Don't just read the headline; ready the actual post as well.

    > ...Porting that runtime layer to 100% Rust, resulting in a pure native binary exposing a C ABI for in-process consumption by all the language front-ends 

C# AOT is relatively nascent and not yet propagated through all of the ecosystem and thus is not a great choice for scenarios where the goal is a native binary with no runtime. Hejlsberg also cited the same reason for the TypeScript runtime. IMO, this is not C#'s strong point and sweet spot; sweet spot is web API backends.

Read my assertion carefully: web APIs are C#'s sweet spot. CLI apps, multi-platform SDKs -- makes total sense to use Rust.