> we already have other languages with new features Not languages that can interoperate with JS the way TS does (except for flow and similar type checkers). T

> we already have other languages with new features Not languages that can interoperate with JS the way TS does (except for flow and similar type checkers). TS success is that it's a superset of JS (unlike say CoffeScript). So you can throw some JS and it will be valid TS. The point of being a superset is that you can add new stuff. Types, enums, annotations. So the only argument why enums are bad except for that it's not in JS? Why does it matter, just because a JS developer has to learn more things if they switch to TS? The whole argument hinges on the premise that TS should not add anything that JS doesn't have except for types, but why is that?