Apple spent years suing MS in the 1980s and 1990s because of claims that MS used ideas from Apple, rather than Xerox, in creating a windowed shell for an OS.
So the days when Apple thought they didn't need to do this were the days of the Apple II.
The Xerox GUI (as implemented in the Star) had no concept of drag and drop or pull down menus. It didn't expose much of a file system (as Lisa and Mac do).
Apple added all that and Windows 1, after the Lisa was launched, opted to also have them. So, yes. Both Apple and Microsoft borrowed a lot from Xerox, but Microsoft really copied a lot from what Apple did.
> so that's pretty much the one original thing they did.
The Star didn't have overlapping windows either I believe (Atkinson believed it did, so he implemented it). I think the clipboard was invented for Lisa as well.
So the days when Apple thought they didn't need to do this were the days of the Apple II.