Earlier quoted context omitted.
Not the GP, but I routinely have use-cases where I switch back and forth between (say) two windows of one app and one window of another app. That, is, for a given task I have a “working set” consisting of windows of different apps, involving more than one same-app window for at least one of the apps. It would be annoying to have to switch between different keyboard shortcuts, instead of just getting LRU behavior with…
My experience on MacOS is that whichever window for a given app was current when you last switched away will be current when you switch back, so it's still a single combo-keystroke to switch as you're describing. My point was that people tend to favor whichever approach they're most used to. Switching only at the window level does "lose" information about the hierarchy, while switching with the hierarchy in place req…
The problem is “for a given app”. If I want to switch back to the previous window, I have to use a different shortcut depending on whether that window was from the same app or not. Similarly, if I want to switch back to the window before that, I may have to first use one shortcut to switch back to the other app, and then use the other shortcut to switch within that app. If the windows represent documents, this roughly means that when switching between documents, you have to use a different shortcut depending on whether the type of the document you’re switching to happens to be the same or different from the one you’re currently on. This isn’t really intuitive, and arguably entails more cognitive overhead.
I agree that a lot comes down what you’re used to, but there are also good reasons to prefer one approach over the other.