Layout Builder is heart of the Sparky Framework. This is something that saves most of your valuable time. When developing a Joomla template, the most complex and the most time-consuming task is to develop the layout. You need to code a bunch of nested DIV containers, then define dimensions for each of them, write CSS code that will support your layout, and finally put elements inside them (module positions, Joomla content, etc.). Even with CSS frameworks (such as Bootstrap or Foundation), you still need to manually write the code, define dimensions for each element and put elements inside them.