Life is so complex. Even simple wheat is not to be taken for granted, as you can read in this news article that explains the time bomb threatening the world's supply, and the multi-faceted challenge of making sure that we can continue to bake our bread.
Sure, there are other grains, but none that contains near the amount of gluten as wheat. Gluten is that unique substance that makes pizza dough (at left) such that it can be thrown in the air and stretched to bake into not only a crusty, but a chewy crust.
And if you've ever tried to avoid gluten in your diet, you might agree with me that the best breads require it. If we have to switch from wheat to rice or rye or triticale, I think there would be a lot fewer homey scenes like this one.