[mrspeaker]

Because it's a slippery slope that you can never get agreement on (even majority agreement on, let alone overwhelming agreement). Why TypeScript? Why not Flow, or even Python or ClojureScript, or (my vote...) PureScript?

Then what happens in 2 years when the "next big thing" comes out that is mind-boggling-ly awesome and obviously obsoletes TypeScript? The latest addition to JavaScript is Array.flat... it should be called Array.flatten, but there was a popular third-party library 15 years ago that used it and you can't go breaking the web every time there's a new "best way" to do things.

Each fan of each language will happily tell you why theirs is better than any others, and why it's the obvious choice to be the default in a browser. Everyone might agree they don't want JavaScript, but no one will ever agree on what should replace it. That's why your two options will only ever be "JavaScript" or "transformed/WebAssembly-fied other language".

[dsego]

Good example, imho better to stop adding stuff to JS, declare it legacy and leave support in browsers so old pages render fine. Then add a new language without compromises like `flat` or `includes`.