Typescript's type system isn't sound and it's overly complicated. Elm's type system is by far more robust, sound, and much much easier to learn and reason about.
Elm went away because:
1.) It doesn't have a "Microsoft" behind it to champion it.
2.) It's a functional languages with "weird syntax" (I happen to think the ML style langs are beautiful, but to each their own)
3.) Probably most important, the maintainers and the community around Elm imploded.
IMO TypeScript’s unsoundness is a red herring. It’s a wise pragmatic design choice, and the alternatives have tradeoffs that were judged to be worse. Whether people run into the particular problems caused by TypeScript’s particular sources of unsoundness is an empirical question. I can’t remember a time it caused me an issue.
Typescript's type system isn't sound and it's overly complicated. Elm's type system is by far more robust, sound, and much much easier to learn and reason about.
Elm went away because: