+1 for this.
I disagree with DHH as I’ve used Browserify with Sprockets before and was able to do true ES6 that way without Webpack.
And even if that’s not the best solution, this post is a cry for help that should not go unheeded. I think there is a need for a better solution than Webpack (or Webpacker). Perhaps ES6 support baked into Sprockets? Or perhaps an intelligent innovative all new solution from the guys who brought us Rails? Anything is possible and would be better than what JS folks offer.
How about finally putting serious consideration into Opal (GitHub - opal/opal: Ruby ♥︎ JavaScript)?
We’re Ruby developers after all, and expect Programmer Happiness without lame excuses.