The Home button is the most used and arguably the most important button on the iPhone. For everyone new to smartphones and to mobile computing, it's an escape hatch that they can press at any time, any where, and immediately be returned to a safe, familiar place. For more experienced users, it's a way to activate everything from Spotlight to Siri, the fast app switcher to the accessibility menu. Because the Home button serves so many purposes, for so many people, the mechanical switch itself is subject to an incredibly high level of use, and potential for wear and tear. That's why, more than any other physical button, the Home button has been a source of problems over the years, for Apple and consumers.