You already got the technical reason: Views hold the compiled functions for rendering those templates. Without the view modules those templates would just be files sitting in your project with no way to use them. So while those view modules may seem empty they for sure don’t stay empty if there are templates for it. That would be more obvious if phoenix wouldn’t hide all the template loading code behind the use MyAppWeb, :view, ….

Also while for html based pages one often uses templates this is not at all the case of e.g. rendering json. There the composition of the output format usually takes place in those view modules directly. Not every format out there lends itself to templating being the prefered method of construction. In phoenix both are cleanly supported by having views be responsible to turn data into some response format, while only the view layer is concerned with the distinction between rendering the format from code or from a template.

It’s also worth pointing out that one of the great things about Elixir is you can pretty much move your files anywhere. I gather all my files together by resource, rather than by type, like:

posts/
  post_controller.ex
  post_view.ex
  templates/
    index.html.eex

Moving the templates just requires a change to the view function in MyAppWeb:

use Phoenix.View,
  root: __DIR__,
  path: "templates",
  namespace: MyAppWeb

Plug is great, as suggested by cpgo.

If you want simpler still check out Raxx