It’s easy to gloss over this stuff as someone who buys new devices frequently, but if you’ve used the iOS 12 beta, the performance focuses of this release makes a difference — even on the iPhone X. The thing that I notice the most is the share sheet.
On iOS 11, pressing share meant waiting several seconds for the activity view controller to start rising up from the bottom of the screen. On iOS 12, the sheet displays instantly. Or at least, the appearance transition is instantaneous. The share sheet lazily loads the contents of its rows, so the OS feels responsive even if it hasn’t quite finished gathering all the third-party extension information that it needs. Occasionally, the sheet pops up and both the bottom rows are just displaying loading spinners. A beat later, the app icons and actions pop in. I assume this happens more often on slower hardware. Regardless, the difference is night and day. Showing something, and populating the complete data a couple seconds later, is so much better from a user experience standpoint than waiting for everything to be ready before starting to display the view.
The iOS 12 performance changes are a combination of these visual touch-ups and genuine speed optimisations. The share sheet is faster overall and presents its UI as soon as possible.
It’s sad that we ever got to a point where the keyboard can be shown 50% faster, but I’m thrilled to see these pain points addressed. It translates into meaningful, real-world, improvements. The overall reception to iOS 12 is going to be very positive because of it. It speaks volumes that performance is the first section on Apple’s iOS 12 features page.
The overhanging question about the focus on performance is whether it can be sustained. It’s great that these improvements are coming with this software cycle, but the impact is mostly moot if iOS 13 regresses and slows down older phones again. Apple has to make a concerted, ongoing, effort to maintain performance on all devices that the new OS versions support.