And this is why I love TypeScript: It's just JavaScript, with a type system. If it's not in the standard then it's not in TypeScript (by default). There's no risk to adoption.
The reason for that is simply that TypeScript has to fit in with JavaScript, while the others do not.
That said, I’ve never found Strong Typing to be that essential for front end dev. TypeScript is incredibly pragmatic, which is why it’s been so successful imo.
Nothing stops people from writing all their dependencies in TypeScript. But it’s not necessary to use it successfully.