I'm fairly confident that many (most?) of the gui elements you listed were invented by Xerox and willfully copied by Apple. Certainly stacking resizable movable windows, pull-down menus, and manipulable desktop items.
The grandparent to your post says "Apple did genuinely develop independently". Not "Apple did legally license from Xerox in exchange for stock". So the point still stands.
The amount of misinformation surrounding how much of the modern computing experience Apple independently invented is also dizzying.
https://en.wikipedia.org/wiki/Xerox_Star