Encoding isn't usually to obscure but to allow using characters not allowed in a URL or wherever text is being stored. This makes it a bit easier to directly take that encoded text later and decode it into something like json.

That makes sense, thank you

> What is the point of the encoding ?

Absence of special characters. No need to escape symbols like {}:/\?& etc, etc.

They have a nested structure, it's a pain to encode that in query parameters.