https://wccftech.com/ipad-cursor-inspired-apple-tv-mac-iphone-x-craig-federighi/

Apple SVP Craig Federighi spoke to TechCrunch to discuss the effort that went into iPad’s new cursor and trackpad support, which took 3 years to develop. The inspiration for iPadOS cursor implementation came from Apple TV’s focus user interface, Mac pointer and iPhone X’s fluid gestures.

Although it seems crazy to go into such details about a mere mouse pointer implementation, it is eye-opening to read the level of details and research that went into it. Apple did not want to simply the same mouse pointer from desktop operating systems to a device that has touch input as primary.