> If an app has multiple windows, contain them within the main app window.
This advice is actually rarely followed by apps regardless of whether they are on Windows or Mac. Consider Microsoft Word; if you open two Word documents, does Microsoft Word open two windows or does it open one main app window and then contain both documents in a single window? Are you aware of this Microsoft concept called MDI?
It sounds like you were used to iOS where each app has but one window and you'd prefer that to be the case on desktop operating systems like Mac or Windows. There's nothing with preferring that, but it's against decades of desktop computing tradition.
This advice is actually rarely followed by apps regardless of whether they are on Windows or Mac. Consider Microsoft Word; if you open two Word documents, does Microsoft Word open two windows or does it open one main app window and then contain both documents in a single window? Are you aware of this Microsoft concept called MDI?
It sounds like you were used to iOS where each app has but one window and you'd prefer that to be the case on desktop operating systems like Mac or Windows. There's nothing with preferring that, but it's against decades of desktop computing tradition.