In short, a better experience has a lot in common with less data, rather than more. Online magazines are increasingly opting for shorter and shorter pages. Some have reduced articles to as little as 5 paragraphs per page, forcing the reader to navigate through 5 to 10 pages to complete the whole article. The reason for this is simple. The website owners want more chances to push advertising at the reader as they are being paid per page impression.
Page size has nothing to do with it.
1 page of 100K is only 1 page impression. But 5 pages of 20K is 5 page impressions. This might be fine if advertising used 0 bytes of data, but of course, it doesn't. The 5 pages of 20K each will probably consume 125K in total to deliver the same amount of content. So, I hear you cry, the user simply switches to sites which use less data.