I've tried rollup a couple of times so far and would always get stuck on certain modules like react and react-dom. I would always have to set up namedExports using the commonjs plugin, which seemed tedious. Not sure if anything has changed recently.

I've never understood why webpack got so much attention either. Both rollup and webpack are much slower than browserify, so I just keep using browserify. And I can get tree shaking with browserify by using a plugin too!