One of the key advantages of a single-page application from the User Experience perspective is perceived response time. It takes well under a single frame refre

One of the key advantages of a single-page application from the User Experience perspective is perceived response time. It takes well under a single frame refresh period (~16ms) to react to some event and either change the page using data you already have, or throw a loading indicator on the screen. The app may have been slower to load the first time (hopefully not by much) but from then on, they get the perception of instant feedback even if they have to wait a round trip for the backing data sometimes. SPA frameworks make this sort of interaction very easy to design and reason about as a developer.