title: create-react-app reduce build size: main.[hash].chunk.js is 3MB+ with mostly images
body: <p>I build my app with <code>yarn build</code>.</p>
  
  <p>It generate a 3.27MB <code>build\static\js\main.8dc5bf7f.chunk.js</code> file:</p>
  
  <pre><code>3.27 MB   build\static\js\main.8dc5bf7f.chunk.js
  82.79 KB  build\static\js\2.61d04f1f.chunk.js
  2 KB      build\static\css\main.275d97bd.chunk.css
  1.93 KB   build\static\css\2.8380becc.chunk.css
  768 B     build\static\js\runtime~main.848c2454.js
  
  The bundle size is significantly larger than recommended.
  Consider reducing it with code splitting
  You can also analyze the project dependencies
  </code></pre>
  
  <p>I used <code>source-map-explorer</code> to analyze the file and it show:</p>
  
  <p><a href="https://i.stack.imgur.com/OTGyX.png" rel="noreferrer"><img src="https://i.stack.imgur.com/OTGyX.png" alt="enter image description here"></a></p>
  
  <p>So the file include all of the images of my entire app.</p>
  
  <p>But funny thing is the build still have a <code>static/media</code> directory which has all of those images in .png form. And apparently the app still load those png files to show the images.</p>
  
  <p>So what are those things in the js file? I wonder if they're even used at all?</p>
  
  <p>Please:</p>
  
  <ul>
  <li>Explain to me why all of the images in my entire application is included in my logic javascript file.</li>
  <li>Is there anyway to remove them? I need to increase page load. 4MB at initial load is unbelievable.</li>
  </ul>