Types at the type layer are not the same as types at the semantic layer. Sure every type in the JSON level has a "strong type" but the semantic meaning of the

Types at the type layer are not the same as types at the semantic layer. Sure every type in the JSON level has a "strong type" but the semantic meaning of the contents of e.g. a string are usually not expressable in pure JSON. So it is with CSV; you can think of every cell in CSV as containing a string (series of bytes) with it being up to you to enforce the semantics atop those bytes. JSON gives you a couple extra types, and if you can fit things into those types well, then that's great, but for most data concrete semantically meaningful data you won't be able to do that and you'll end up in a similar world to CSVs.