In context those are just tweaks ... Xerox designed the entire WIMP (Windows, Icons, Mouse, Pointer) UI concept, including the bitmapped display it is based on, first commercial mouse, ethernet networking ...

Xerox's invention was visionary and pioneering. Apple's was just engineering iteration.

It's as if one company designed the automobile and you want to give outsized credit to someone else who added turn indicators.

The desktop metaphor absolutely was in the Xerox Star and that was copied by the Lisa team (and carried over to the Mac) after they viewed it when Star was first announce. That’s well documented. The Star also had limited pull down menus mostly a single menu item on the top right of every window that was hamburger-like in design that had items in it.

The Xerox Development Environment (TAJO/XDE) was more windows like where windows were processes and shrunk down to the bottom of the screen when closed. Star was developed using Tajo but are completely separate systems with very different user interfaces. For example Tajo used cut/copy/paste and any window could be set overlapping where as Star use a MOVE, COPY where use selected the object pressed the verb action button, and then selected the destination (use that was modal!). Also Star choose to have non-overlapping tiled windows (except for modal dialogues & style sheets.) The windowing was changed in later versions to allow any window to overlap.

What’s even more confusing is that Xerox had lots of systems including smalltalk, interlisp, star, Cedar & Tajo at the time Lisa was released. They also had lots or prototypes systems including Rooms and the Alto for that matter.

Apple absolutely also did their own research and design that was unique. And in cases the duplicated earlier research but came to a different conclusion (for example the number of buttons on a mouse.)

I think Apple did more with direct manipulation than others did taking it to more extremes — but you can still see that in other earlier systems.