I don’t think Xerox invented this. They developed the PARC system.
PBS did a series on the history of computing and had a guy in a video clip demonstrating a mouse, point and click, WYSIWYG, and Icons. I think he was the pre-curser (pun intended) to everybody else.
PARC was Xerox’s r&d department, so I don’t think it’s out of line to say Xerox invented them.