and are limited to using just one finger at a time (because your eyes can only focus on one spot at once).
That isn't entirely accurate. It's not because you focus at point x, that another finger cannot be moving at x + y cm and perform the correct action there. I never learned to type blindly. Or at least not in the way this is normally done. However I do have enough muscle memory by now that I can look down at the keyboard, put a couple of fingers in what roughly looks like the right spot and then start typing away with multiple fingers, from time to time laying focus in the center of the keyboard only.
That isn't entirely accurate. It's not because you focus at point x, that another finger cannot be moving at x + y cm and perform the correct action there. I never learned to type blindly. Or at least not in the way this is normally done. However I do have enough muscle memory by now that I can look down at the keyboard, put a couple of fingers in what roughly looks like the right spot and then start typing away with multiple fingers, from time to time laying focus in the center of the keyboard only.