The observation is that a series of closely timed delays are experienced as a single, longer delay - or interaction - by the user.
The upshot of this is that a site where all pages are cheap but there are more of them may be more pleasant for the user than a small number of kitchen sink pages (finding stuff with the scroll bar is also slower). However, very very few of my employers have been willing to sign onto this.
Everybody wants their stuff on page 1. Page 2 at the least. Only losers have their information on Page 4. And if your stuff in on page 20... think of the shame. Can you even face your family for the holidays anymore?
What's really fucked up about this is that people consider carousels to equate to being on the front page. There are websites where I could visit literally every single page on the site in less time than it takes for the goddamned carousel to finish doing its thing. The inmates truly are running the asylum right now. Which is why I've done the Homer Simpson in the Hedge maneuver into backend work.