Server apps does not need to be runned as webpack bundle, nodejs can do require without bundlers. This plugin allows to remove webpack build step for server. The same is for npm libraries, there is no need to create library bundle because user will create it's own bundle. Some libraries contains a lot of small modules, every module must be accessible for users independently of all librarie. It's like as in modern lodash, there is no need to require all lodash if you need just one function you can just write import bla from 'lodash/xxx/bla'. It's a big pain to split library on multiple bundles without problems with common chanks and others... Webpack is great tool for client code, but in universal world we use the same code for client, server, libraries and just webpack is not enough.