WASM isn't yet a viable candidate for a complete application. There's a lot of proposals out there to bring it in line with what you can do via JavaScript, but

WASM isn't yet a viable candidate for a complete application. There's a lot of proposals out there to bring it in line with what you can do via JavaScript, but there's still a lot of things that JavaScript can do more performantly than WASM. Using a WASM language also means that interop with existing JavaScript is a bit of a hurdle, so I still feel that Dart is a good choice. That being said, there's nothing particularly interesting about the language itself; I'd feel the exact same way about any other language if they also compiled to pure JavaScript.