Deep analysis of a modern web site [pdf]

This analysis shows that websites are increasingly composed of many assets spread across many different servers. And it suggests that trying to go against this heterogeneity trend is wasted effort, as CDNs are always improving.

That said -- are there teams out there actively trying to centralize everything? e.g., pre-computing all the assets needed to serve a page and delivering it in as few bundles as possible from a single host?