And furthermore, sharing frameworks has been responsible for the incredibly fertilization. When you consider the recent pace of Javascript development - with jQuery, and now React, we've had years of huge, newly-developing libraries, plugins, communities, and sites-becoming-apps. Turns out, you don't need to effuse limitless creativity when creating a viable web app. You need the same few things over and over, and you'd rather use something with a lot of extendable pre-written code. Facebook built React/Flux because they saw their apps facing a very similar set of problems over and over again. By sharing this admittedly large and ever-shifting set of tools, javascript development has had some terrific momentum.
In some ways, once an organization has really settled into a set of linting rules, testing coverage requirements, shared components, and code review adhering to a style guide, you're freed from all of that pesky creativity. You can just write the thing you have a spec for by reasoning about the minimal data you need to represent the possible states of the app. You eschew choices, and your collaboration is easier, less egotistical, and more productive.*
*Written by an idealistic bleeding-edger.