TS language server will do that for you as go along

Wouldn't that defeat the point of what static typing affords you? Before you "go along"?

No, during development your IDE will show you type errors and your dev server can ignore them. In CI tsc can type check. It's the best of all worlds: incorrect code will compile and work best-effort, you can see errors in your IDE, and CI will fail if it's incorrect.

You can have the code running in your browser instantly and have the typechecking happening in parallel while you develop.