Page layouts help to organize content.  For example, a two or three column layout helps to organize long articles which could be difficult to read were they placed in a single column format.

Home pages have a fixed format.  It is the "Main Area 1 Secondary" below.  Frankly, it is also the most useful, for the layout ratio approximates 2/3 - 1/3.  This provides enough room for text on the left side of the page with pictures, annotation, or lesser important information on the right.  Both sides allow for the addition of multiple text tables.  And text can be added in the runner area which is always a single column layout.  However, with text wrapping and left / right justification, it is possible to create the appearance of columns.