Apple’s staff can design the magical gadgets you have in your hand. They can even program all the software, and run the services such as iCloud and Siri in the U.S. But they can’t produce the hardware fast enough and supply America (and the rest of the world) at the rate we demand.
But the average consumer doesn’t take “no” as an answer. Upon hearing there won’t be new iPhones, that they are delayed or not in stock, we slam our fists on to the table and demand satisfaction. We wave our money in the air yelling “I need one”, and money makes stuff happen.