It still baffles me that it's so hard for anyone other than Apple to make a single well-polished device, all the way through. If someone gets the casing right, they'll still mess up UI transitions that are meant to be seamless, create laggy or inaccurate touch input, fail to run at 60 or 30 fps, or make hilariously ill-informed UI decisions in the most frequently used apps (clock, settings, camera, ...). What's the explanation for this phenomenon?