I mean, I was able to build my own single page app in a few hundred lines of javascript front-end code, and a few hundred more lines of javascript for some interface elements.

See: https://www.futureclaw.com

This also includes server-side rendering of the initial page.

I didn't use Angular or React or Ember or any other framework.. I just went ahead and made my own with ES6. The latest Javascript ES6 makes all of this easier.

If you're worried about complexity, just ignore the existing frameworks and do it from scratch.