Well: Static types exist at runtime, VM can optimize using type information (Inline caching, Devirtualization, predictable, fixed object layout), AOT compiled, Dart’s type system is sound, language-supported Isolates (wow feature), hot reload at runtime (wow feature) since Dart can patch classes and functions in memory.

That's a really good list. Thanks. I also miss type annotations not being reflected at runtime (like in Python). Would be great for things like schema validations at runtime. That said, I understand the challenges: that would require changing JS, and that would make JS files larger.