Yeah, depends on the type of app / webpage of course. E.g. a blog doesn't need any of that, but a webshop does. But there's also a middleground where most of the code runs in the browser, while only some small parts need to run on the server (like login/auth, or a "cloud drive" storage). IMHO this type of web application is currently the most interesting.

PS: how complicated that is all depends on the library ecosystem IMHO.