Sure but they all end up being used as a build tool. Webpack may be a module bundler, but it has hot reloading, live reloading, and plugins to transpile. Watch any React tutorial and the first thing they have you do is set up a Webpack config that gives you a live-reloading build system with ES2015. And it's a different one than the one I used 5 months ago.

It's nice that there are people willing to address problems, but it would be nice for web development to grow out of its "oooh shiny" phase.