But it seems obvious that if "coffee" gives 2 billion results that, no, you're not going to be able to browse to page 187,398,384 to get those results. There's no use case for that for any normal consumer (as opposed to competitor, researcher, etc.). If you're capped at browsing the first 10 pages or whatever, that's entirely reasonable.
> A misconception regarding Google’s search results is that all of the results are being served to the user conducting that particular search.
That misconception lies only with the author. Nobody's being "served" 2 billion results, I don't even know what that would mean. The number of results being reported is quite obviously in order to allow users to judge the breadth of search queries. If it says 2 billion, you might want to refine. If it says 15 and they're all useless, go broader.
(It's useful for researching item popularity too, although that's been superseded by Google Trends which is built specifically for that.)