I heard webpack is in now. Grunt and Gulp have gone the way of the <marquee> tag.

It was used to hack together build pipelines since the tools didn't fit together nicely, creating hard to debug messes which we grew tired of. Those hacks can be replaced with webpack and you're often left with a few snippets that fit nicely in the script section of package.json (npm scripts). Gulp is still useful for some projects, but a lot less often.

I liked gulp, but it does seem like webpack has the mindshare going forward. If your using the Angular CLI then your project is using webpack.