Not that TypeScript doesn't have it's pain points but having tried Dart on an Android application recently, there are so many things I dislike about the language and it's ecosystem compared to modern TS/JS. I feel like it would have been a lot better than JS when it came out but now it's painful to use in comparison.
Definitely my preferred route for building mobile apps now though.
I now actually prefer Dart for services and glue code on the backend. I'm so tired of dependabot yelling at me about my hobby projects every week that have yet another vulerability in one of their million dependancies. In Dart I make do with just a handful of deps, then build a binary and call it a day. I tried using Deno with TS, but binaries it generated where absurdly big, 70-100MB depending on the target platform. Also, Deno's --allow-X thing becomes tedious after a while.