This idea struck me when eating my 2nd chicken sandwich of the day and I realized that the bun had been squished into a square shape. Something that doesn't make sense is how typical white sandwich bread comes in a square loaf while any restaurant will give you a round bun that leads to all the ingredients falling out. The main benefits of the square bun are simple, firstly it allows for a more even spread of ingredients like bacon or tomatoes which often end up falling from round buns and not being in every bite. The second benefit of square buns is that they are easier to package and transport without crushing them as you can just slide it into a box with almost no gaps so there is no bouncing around or movement of any kind.While most people would not pack a sandwich or bread in a box, the shape still makes it easier to pack in other ways, for example you have a sandwich you want to take with you but the buns are round so you have to either put it in a box that lets it slide around or wrap it in something, which will not be even at all, so you only have bad options. Now imagine that the sandwich had square buns, you could put it in a box and it would not slide around if the box is the right size, it also would not spill out the top because the whole sandwich is covered in bread on both top and bottom. If you were forced to wrap your sandwich, the process would be simple because the sandwich is perfectly square so you can actually know how much wrapping you will need at a quick glance. All in all the benefits to transport, and distribution of ingredients make the need for square sandwich buns very clear.