[zorr]

As explained in a sibling comment, the toolkit cannot make assumptions about restoring an apps window state to its previous size. Sure it might work for simple hello world apps that always open the main window, but that's not always the case. Sometimes applications have to open a different window or multiple windows on app startup. The only thing the toolkit can reliably do is translate the requested window size when an application opens a window to the DE so that the DE/WM can place it on the screen.

Because of the dynamic nature of opening windows, app developers should have control over storing/restoring the window size. Simple apps might always store the last window size and restore that exact size on startup. Other apps might have to run some logic first before they know how large the window should be, and then request the toolkit to create a window of that size.