In reality there are too many context clues and we, as humans, can only interact with one application at a time. Any argument against global menus are really unfounded - the only argument that holds any water at all is one of what you are used to.
People at the end of the day just want to use what they are already used to - whether global menus are superior or inferior is really moot because most people aren't going to get past the "what they are used to part" and will deride it largely on that alone. This is coming from a Windows user that only started to use macOS after like 10 years of Windows usage and no really liking the global menu, or one click mouse and numerous other things about the Mac, but gave it a shot any ways as initially it drew me with its nice looks, but then the UNIX underpinnings & POSIX compliance kept me with the platform. I wasn't even looking for UNIX or POSIX either at the time - but it is now an invaluable part of my workflow, as are global menus and Cmd key positioned for my thumb, not my pinky.
I wrote https://kinto.sh to help bring over the shortcut keys I am used to as well to Linux and Windows.