TS is about readability and maintainability of code at scale. Having types helps immensely in understanding a new codebase and working in a large codebase with many other people.
The problem is Javascript has been entirely commoditized by enterprise, so solutions which should only be relevant to "code at scale" have become mandatory at any scale. You practically can't distribute a Javascript library without writing it in Typescript and submitting it to NPM, with the build step expected.
Yet writing even complex javascript without Typescript and having it work is still entirely possible, just as it is with other weakly typed languages. There should still be room for that, but the concept of simply writing javascript has become so alien it needs to be reintroduced as "vanilla javascript."
