As a corollary to that I suggest people do some research into Webpack 2. Much as I like rollup's simplicity, Webpack 2 looks like it's here to stay and now that it supports tree shaking, it can replace rollup. It's worth understanding how it works even just because many tools assume the use of Webpack.
For example, Preact, which in many cases can be a drop-in replacement for React at a fraction of the size, gives instructions on how to use it with webpack (to alias react and react-dom), but not Rollup.
The Webpack 2 guides are not great, but much better than what came before, and I'm sure many blog posts will continue be written on the subject. And ultimately it's not really that difficult to get at least a decent grasp of its concepts, and it pays off in the end.
For example, Preact, which in many cases can be a drop-in replacement for React at a fraction of the size, gives instructions on how to use it with webpack (to alias react and react-dom), but not Rollup.
The Webpack 2 guides are not great, but much better than what came before, and I'm sure many blog posts will continue be written on the subject. And ultimately it's not really that difficult to get at least a decent grasp of its concepts, and it pays off in the end.