Considering arguably the keyboard itself is one of the most common "touch surfaces" on iOS, the level of neglect and level of overall quality is staggering. There's some serious incentive problems at Apple if nobody is tasked with making one of the best digital keyboards in the world.
PS - Whoever came up with the concept, on swipe-style touch keyboards, of the "Tap Map"/Heatmap wherein keys visible location doesn't match their touch area - so that BY DESIGN it always provides an inconsistent user experience needs to be fired into the sun. You literally cannot disable it on most mobile keyboards. It is on iOS's native keyboard AND Microsoft's Swiftkey.