The week iOS 7 launched, designers worldwide split into two camps — one felt 'kicked in the temple,' the other felt 'finally, no more drawing wood grain.' The truth was: screen resolution had improved. Retina displays let the screen carry large fields of pure colour, with no need for shadows to 'fake depth.'

Around the same time, Google Material Design (2014) added a subtle 'paper shadow' sense of depth to the idea; Windows 8 Metro (2012, actually earlier) was even more radical than iOS. Three tech giants voted in unison, and the 20th century's skeuomorphic aesthetic was pulled from shelves within 18 months.

Flat's danger: when every app uses iOS Blue · System Red · System Green · System Orange, the whole world starts to look identical — the term 'flat fatigue' appeared as early as 2016. Today's solution is 'Flat 2.0': keep flat's cleanliness, but add back a little shadow, gradient and motion — a path that runs all the way to today's iOS 26 and Material 3.

Its greatest legacy isn't visual — it's the value of 'consistency': all apps must look alike, buttons sit in the same place, icon styles are unified. The first time you tap the right button in a brand-new app, you owe 2013's iOS 7 a thank-you.