I loved Brunch back a few years ago. But I wasn't happy with how plugins worked, or their "all files get included in your bundle even if you never required them".
So I built my own build system on top of Gulp, and added a set of tasks using browserify for web apps (https://github.com/BraveNewWorldDev/parched-example-app). It's heavily "convention over configuration", like "npm install parched-babel" is all you need to get Babel integrated.
I'm still using it in production on websites, Cordova apps, and Electron apps, but I'd still recommend webpack nowadays since that's where the community is.
So I built my own build system on top of Gulp, and added a set of tasks using browserify for web apps (https://github.com/BraveNewWorldDev/parched-example-app). It's heavily "convention over configuration", like "npm install parched-babel" is all you need to get Babel integrated.
I'm still using it in production on websites, Cordova apps, and Electron apps, but I'd still recommend webpack nowadays since that's where the community is.