Keys could be rendered useless if you were unlucky enough to have dust particles- dust particles!-get under the keycaps. Apple's design took up less space, but it inadvertently made the keyboard more prone to failure. Apple's desire to make its laptops thinner and lighter ended up with a mechanism that allowed for less key travel-the amount each key moves when you press down on it-over a traditional, more bulky scissor-switch system. From broken keys that pop off to keys that don't register at all, we've all heard constant complaints about MacBook keyboards ever since Apple introduced its new "butterfly switch" in 2015.