For better or for worse, Python doesn't do typing well. I don't disagree that I prefer well defined types, but if that is your desire then I think Python is perhaps not the correct choice of language.
Golang does typing, but JSONs are PITA to handle.
Try parsing something like `[{"a': 1, "b": "c", "d": [], "e": {}}, null, 1, "2"]` in go.
Types are a bless as well as a curse.