XML or JSON - does it matter? Turtle is a turtle, same principals apply, just different structure. What happened to server side rendering? Oh, we do that with fancy frameworks and ton of JS now. All good.
A while ago I stumbled over a corporate site and decided to open the dev tool on a whim. Turns out it's all XML styled with XSLT stylesheet instead of the usual HTML+CSS. I forgot the name of the site and haven't found another site that do this since then.