ClassVersion.js

class Foo {
  constructor($http, $log, WhateverElse) {
    // This is the boilerplate I'm talking about
    this.$http = $http;
    this.$log = $log;
    this.whateverElse = WhateverElse;
    // anytime I add something, I have to add it here
    // anytime I remove something, I have to remove it from here
    // I just don't really see what classes are getting me from
    //   a reusability/maintainability/readability/whatever standpoint.
  }
  
  doSomething() {
    return this.$http.get('some/url').then(response => { // <-- thank you arrow function! lexical scoping
      this.$log.info('Got something', response);
      this.whateverElse(response);
    });
  }
}

FactoryVersion.js

function Foo($http, $log, WhateverElse) {
  return {doSomething};
  
  function doSomething() {
    return $http.get('some/url').then(response => {
      $log.info('Got something', response);
      WhateverElse(response);
    });
  }
}