[heygrady]

Babel is both the driving force of innovation and the cause of much of the fragmentation in JS. Babel allows you to use the latest language features and target the oldest environments. The trouble is that there's not a "right way" to package software to cover all of the deployment concerns. Code needs to work on Node going back several versions as well as browsers going back several versions. And for mobile/desktop websites, your code bundle size is extremely important. Rollup and Webpack 4 go a long way towards making this easier but it's nothing close to a "standard best way" to do it.

[danpalmer]

That's a good summary of the fragmentation and coupling in the build tools, but there's also the libraries themselves - React, Redux, React-Router, React-Router-Redux, etc etc.