Package manager (e.g. NPM) for shared libraries in browser

Today, each web application packages all its dependencies (often a very deep npm tree), every time we open it. A large number of JavaScript libraries are the same (e.g., ReactJS, Bootstrap, @fortawesome/fontawesome-svg-core, node-sass, etc. etc.) they don't need to be loaded for each website, or web app. The browser could provide the shared dependencies, that all web apps could use.

If the browser would have these libraries shared, then we wouldn't have to use so much traffic to load them from every app every time, that would reduce the traffic footprint for downloading app dependencies.