The esri-loader library hit the 2.0.0 milestone this week. This release doesn’t add any features, but merely removes the old callback APIs that were deprecated when we introduced the promise-based ones in v1.5.0. If you’ve been using the new APIs, you can save yourself a few bytes by upgrading to 2.0.0. You can read more in the 2.0.0 release notes.
One does not simply load modules from the ArcGIS API
If your ArcGIS web application uses any other module loader besides the Dojo loader (i.e. webpack, Rollup.js, etc.), you should be using esri-loader.
That’s a bold statement, so let me back it up.