There's a big discussion about this: https://github.com/microsoft/TypeScript/issues/1897. The benefit seems extremely limited to me. Valid JSON is obviously a subset of `any`, but I can't think of a situation where that particular specificity provides any value. Can you?
The value is when you’re parsing the JSON afterwards. It’s good to know you can match it exhaustively -- each value is either a Record<string, Json>, Json[], string, number, Boolean or null, and nothing else.
Edit to add: I think “any” is almost always a big cop-out because you couldn’t be bothered figuring out the correct type, and it often causes problems (loss of type coverage) further down the line. I admit I do use “any” in my own code when I really need to, but a library should work harder to avoid it, and the standard platform typings should work harder still.
