I notice also that in these projects, every pull request takes many files. Whereas in an Angular 1 project there would be an update to a template and a controller, now each PR comprise updates to a reducer, a container, a component, a saga, a 'lifecycle component', an action creator, and a props schema.
As for Webpack, I don't understand the popularity. I find configuring it awkward, not least because it relies on third-party plugins of highly variable quality. Most plugins are very poorly documented, and those that aren't invariably seem to have big fat DEPRECATED notices. It seems that any plugin that makes enough assumptions to be useful is inevitably chucked in favour of something that is totally configurable but by default equally useless. YMMV.
At least with Gulp, I could step through a build process and write a little bridging code when two plugins stepped on each others toes. Webpack doesn't give me any such chances.