The biggest advantage of client-side rendering is that clicking a link doesn't require a full-page reload. Dynamically updating small portions of a page allows for a more snappy experience, especially when on a cellular data connection.

Right and wrong. If that’s all you need to do search for SennaJS or PJAX. What really f/e frameworks and libraries help you build is complex interactive interfaces. If you don’t see their use then means you don’t need them.

Yes. If people are using full MVC frameworks for the sole reason of avoiding page reloads then they really need to look at PJAX etc.

I can add PJAX to existing Django sites in about half an hour. It degrades gracefully, allows me to carry on generating my HTML on the server in a language I prefer and carries a very small cognitive overhead.

I understand TurboLinks in Rails is essentially the same concept?

Yeah, TurboLinks is the Rails counterpart.

To clarify a little: I personally use SennaJS a lot and React. They are two different things for different goals.