Everybody seems to want that, except for the people who work on Typescript, who argue it'd be the wrong tool. Typescript's types simply aren't able to provide

Everybody seems to want that, except for the people who work on Typescript, who argue it'd be the wrong tool. Typescript's types simply aren't able to provide input validation, both because they don't exist at runtime and for lack of power ("number must be 0..10"). At least with Zod, you also get Typescript types, from the same schema.