Three reasons off the top of my head: - Smaller cacheable objects -- every change you make doesn't invalidate the whole "bundle". - If there are many permutat

Three reasons off the top of my head: - Smaller cacheable objects -- every change you make doesn't invalidate the whole "bundle". - If there are many permutations of the optimal bundles: different browsers, different pages use different scripts, etc. - The browser does not need to wait for the "full bundle" to download to execute your app/site -- it can start once the first necessary assets are loaded. In one project I worked on, we had 3 bundles: - early load (inside the head tag) - deferred load secondary (after body tag, for the other site pages) - deferred load primary (after the body tag, for the 'hot' pages of the site) With a optimal http/2.0 setup, we wouldn't need to make these never fully optimal bundles.