All this time I've just been using a boring old shell script that runs browserify with the Babel plugin, and then uglify. Hook it up to npm scripts and I've got all I need, in about half a dozen lines spread across two files.

Browserify is useful because concatenating a bunch of JavaScript files is hardly the right way to be doing things. Babel I have to use because all browsers struggle with ES2015 to an extent. Uglify to minify it all.

But all these other tools? Never had a use for them. Never used grunt or gulp in a new project, and in those that I've looked at which do, they don't really make anything easier.