What you’ve just described is absolutely the opposite of what I want. Mobile apps have very different requirements than desktop apps, not least as the metaphor

What you’ve just described is absolutely the opposite of what I want. Mobile apps have very different requirements than desktop apps, not least as the metaphors are wildly different. macOS, Windows and X all have fairly similar window layouts and behaviours. iOS and Android have sharply different layouts and behaviours. Yeah there’s a bit of overlap now, but even navigation is different.