I totally agree - the example they give doesn't really need react OR backbone. You could just as easily show vanilla js as the 3rd example and wonder why you would ever even need a framework.

One off it seems fine, but a huge backbone app gets really complicated for me. Show me a huge react app vs a huge backbone app and I will understand the react much more quickly.

"It's verbose, sure, but there's no mystery. A junior developer can trace exactly what happens and when. The mental model is straightforward: "when this happens, do this."

I don't think that's true. A large backbone app has a lot of code that you'll have to trace through multiple files in different directories - the template are here, the functions are there but the endpoints are over there and... maybe it's just the backbone app I have to update but it's much more confusing and abstracted than the react app I also have to update. And don't even get me started with adding a new component. I can drop a new component into the react app and import it anywhere and it's super fast and easy... backbone not so much.