Buttons are one of the most ephemeral parts of modern technology. A text file from a decade ago will still load the same, a dead console’s games can live on in emulators, and as the adage goes, nothing is ever really gone from the internet.

But even the best button is doomed to fail. As the only physically moving part in most modern tech, buttons are the one element that can truly, permanently wear down or break.

And nothing illustrates that reality quite as much as the iPhone’s home button, a textbook illustration of how that crucial flaw can affect a product and shape it over time.

As iconic buttons go, the original iPhone home button is up there among the most famous. Ask someone to draw a smartphone, and until the last year or so, odds were that they’ll come up with a black rectangle with a circular button on the bottom. Show someone a zoomed in picture that just presents the rounded, square icon printed in its center, and it’s immediately identifiable as an iPhone, even without any other distinguishing information.

It’s the button that taught people how to use a smartphone, but it had one key problem: it was one of the iPhone’s weak points, a mechanical point of failure that would wear down over time and a point of ingress for water to flood the fragile interior. In some countries around the world, fears around the home button’s fragility reportedly led vast numbers of people to enabled a virtual home button, using the on-screen option out of concern that regular use of the physical button would break it.

Eventually, something had to change. In 2016, Apple released the iPhone 7, which replaced the home button with an unmoving, solid circle that wasn’t really a button at all. Thanks to a new haptic feedback engine, users could still “press” on the home button area and feel a fake click, but the “button” didn’t move. Deserved or not, the concern over iPhone button failure had reached the point where Apple had to design a wholly fake button around it.

But the button also had other problems: it took up a huge amount of real estate on the front of the phone at a time when screen sizes were growing, and it was increasingly inelegant to use in a world of touch controls. And Apple’s faux button, while function, simply wasn’t as pleasant to use on a tactile level as an actual, real moving part.

And so, with the iPhone X, Apple completed excised it in favor of a screen-based replacement that completely eliminated any concerns about the button from the iPhone for good. Because ultimately, the home button — even the haptic-powered, fingerprint-reading, touch-sensitive version that Apple had reached in its final iteration — could still be rendered obsolete by the march of technology and the inherent limitations of physical hardware.

In the iPhone’s case, it was a gradual shift that took years to happen. But even for something as important as that home button, the sacrifices were too great. Even the best buttons are still buttons, and eventually, every button fails.

But there’s a silver lining of sorts. Sure, today’s iPhone doesn’t have a home button, but the phones are more waterproof than ever. The screen is bigger and can show more information. And the gestures that replaced the home button have turned out to be much better for actually using Apple’s software, letting users fly around the OS and between apps in a way that the punctuated pauses of the button presses never allowed.

Apple’s home button may have been iconic, but its flaws eventually forced the company to design around it, bringing about a better version of the product than the one that the button itself had offered.

Because sometimes, a button isn’t always the best answer, and that’s okay too.