When you are making bread each time you punch it down, you are creating a better bread, by adding air bubbles to the dough. When you press down the top of the focaccia bread and then create the dimples in the bread you are preventing it from rising too quickly. If the bread rises too quickly these air bubbles will burst. The indents in the bread are also a great place to add some extra flavor. Whatever seasoning you decide to add to the bread can be pressed into the dimples and then the bread will rise around it and then the flavor will bake inside.