I think this varies wildly on the type of app you're building. If you are building something like CRUD interfaces obviously a server side focus is very viable and useful since you don't have to have double state management. I am thinking apps like ecommerce, banking or management software.

But if you're building a very client heavy application that does something like Photo editing, CAD, video editing etc I have a hard time seeing a server side generated content to be successful because you need a lot of client side state no matter what.

For example, I have done a lot with maps and it's not possible AFAIK to render the canvas on the server since it's a browser only api. Also I don't really see the benefit since it takes too much computational power to generate graphical things on the server.