Google Maps would be the classic example of client-side refresh working so well that it's now the universal choice. At the time, it was a revelation, as the Mapquest-ish predecessors (if I recall) required a click and server-side refresh to scroll or zoom the map.

Of course the revelation here was that <a> tags weren't what we needed to move a map, but rather a click-and-drag plus scroll-wheel behavior to explore a huge image at various levels of detail. If the server-side page-by-page navigation paradigm is a lousy fit for information delivered over the internet, then it may make sense to re-invent the page load.

To use the language of a sibling comment, this brought things to a much more app-ish behavior. And eventually Internet maps have become, especially on mobile devices, an app. Hence the need to break server-side navigation may have foreshadowed the need to break out of the browser.