Ah yes, I didn't realize "ember build" produced a development build. For comparison, create-react-app always builds in production mode to eliminate this exact scenario!
I think that's probably a good change to the default. Today, `ember build` is analogous to `ember s`, and most people deploy to production with `ember-cli-deploy`.
I just tried a new ember 3.15 app production build, the JS payload comes in at 712.29 KB (180.80 KB gzipped)
`ember new myapp && cd myapp && ember build --environment='production' && ls -la dist/assets`