I'm not a mac user (but a linux user who chooses desktops with the windowing paradigms of like windows 2000 or so plus multiple desktops) so have no idea how it's like in practice, but:
These days it's very common for more than half your work to take place in a browser, with many browser windows, each having many tabs
Every window of the browser almost is like its own application for the user, yet they're all from the same application with the same name for the OS
How does an application switching interface, rather than window switching interface, work out for that, if a lot of what you want to switch between is different windows of the same browser?
(and what if in addition there would be also many terminal emulator windows, each also with many tabs, and maybe some code editors, spread across multiple virtual desktops)
These days it's very common for more than half your work to take place in a browser, with many browser windows, each having many tabs
Every window of the browser almost is like its own application for the user, yet they're all from the same application with the same name for the OS
How does an application switching interface, rather than window switching interface, work out for that, if a lot of what you want to switch between is different windows of the same browser?
(and what if in addition there would be also many terminal emulator windows, each also with many tabs, and maybe some code editors, spread across multiple virtual desktops)