> Every time you use a mouse, you have to re-orient your self to the state of the mouse (its current location and its use within a given application). That is why we spend so much time optimizing applications for use with a fixed controller (a keyboard).

No. This is wrong. The mouse is faster. Apple did that research, too -- and the mouse won every time:

https://asktog.com/TOI/toi06KeyboardVMouse1.html

Recognizing and pointing is always faster than remembering command sequences you have to press/type in. It imposes less of a cognitive burden too, which means you can focus more on the task you're doing and less on the interface itself.

Apple absolutely made the right call with a mouse-centric UI in 1984 and they made the right call with touch in 2007. That's why they're Apple -- you don't become the most successful and influential tech company in the world by making stupid choices.