Earlier quoted context omitted.
Yes I think it is, In Mac OS it has always been explicit that an application ≠ window (with only a few exceptions such as the calculator app). Closing an app window must not quit the application. This is reinforced by the menu bar which is always at the top of the screen rather than attached to an application window.
Why is that? I'm a gnome/Linux user who had to switch to Mac M3 for work. Macos feels.... Half baked. I don't understand why apps should run after I close the window. I'm also annoyed that I can't type the window I want when viewing all windows. If I open mission control, it takes 3 clicks on the dock to run the app. (Un-do mission control, focus the dock, run the app.) That being said, I do like stage manager, I try…
The closest they’ve gotten is iOS itself where apps sleep forever without your interaction.
In the very early days of macOS before becoming a Unix it was actually noticeable because for ordinary people they apps they would use would always be around, and it was still faster to swap in running apps than load a closed app from disk.