Quick note I perhaps should have clarified, I wasn't thinking about the Mac's "full screen mode". This was something I noticed about other students in my high school a decade ago (why it's coming to mind now, I have no idea), before full screen mode existed on Mac.
It used to be that if you clicked the green button on Mac, most apps (not all apps, for weird aqua-UI reasons, but certainly web browsers) would grow to fill the screen without outright hiding the menu bar and dock, just like the maximize button on Windows.
My experience pre-full screen on macs was that the green button would do just about any random thing except make the window fill the screen. It would certainly change, usually it would fill vertically (but not always) but almost never horizontally.
To this day I still rarely press that button because of years of it doing nothing but unpredictable nonsense.
It used to be that if you clicked the green button on Mac, most apps (not all apps, for weird aqua-UI reasons, but certainly web browsers) would grow to fill the screen without outright hiding the menu bar and dock, just like the maximize button on Windows.