Camera launches up to 70 percent faster, the keyboard appears up to 50 percent faster and typing is more responsive. Even when there is a lot going on across the system, apps can launch up to twice as fast. From iPhone 5s, introduced in 2013, to the most advanced iPhone ever, iPhone X, iOS 12 brings performance improvements to more devices than any previous version.
This isn’t just a new-features thing — it’s a security thing too.
Manufacturers are often playing a game of cat-and-mouse with exploits and hackers; every update eliminates any number of vulnerabilities, and the more nefarious folks need to start looking for alternative ways to compromise your device. However, once a device maker stops pushing out updates, it’s only a matter of time before your device becomes susceptible.
Update: It helps to remember — at least for me — that not everyone can afford to or desires to keep up with Apple’s yearly iPhone upgrade cycle. For folks that keep their devices for many years (iPad users in particular), this extended approach to compatibility, security, and performance is huge.