Pagination -- from a user's perspective -- has nothing todo with computation.

To appreciate what pagination does, just imagine a 500 page book. Now imagine having to read it on an ancient scroll. Pages make it easier for our brains to segment the information of a book or a long article by giving us a higher order rhythm within the content.

Or just take it one step further: why not eliminate line breaks? They're just as arbitrary as page breaks and there is no technical limitation on horizontal scrolling. But again, segmentation helps to form a mental model of the content.