I'm clearly biased, but at least in my experience, while this is technically true, you're still dealing with XML (and now JSON) shoehorned into a tuple-based context. In other words, there is still a (lossy) translation layer, it just happens to be in the RDBMS rather than in-app.

Fauna's advantage here is that this way of structuring queries is deeply integrated with the language (and underlying wire protocol) itself. For example, Fauna's response format supports returning independently iterable result sets (supported by cursor-based pagination under the hood), allowing you to lazily populate the result graph in your app based on further user interaction.