Forget texting from pocket. Consider why we can't really operate any of the common touchscreen devices, like phones, tablets and computers, without looking at them. It's because of unpredictable input latency, unpredictable UI timings, and unpredictable UI behavior all across the stack - from the apps with bullshit flashy UX, down to the OS which is not a real-time OS, and will introduce arbitrary latencies for arbitrary reasons.

The touchscreens and their driving hardware is itself fine. It's the introduction of a proper, non-real-time OS, that's the "original sin" here. Everything else is just decades of practice of writing for such OSes, with the fundamental unstated assumption that interactivity means user is looking at the display while operating the device. This assumption bleeds all the way to the very core of *nixes and Windows.