For a UI consistency is better than dynamic elements. In fairness this can be used as an argument in favor of the global menu too, depending on exactly what you

For a UI consistency is better than dynamic elements. In fairness this can be used as an argument in favor of the global menu too, depending on exactly what you want to be consistent. Linux desktops are usually "focus follows mouse" (because the scrollwheel is part of the mouse not the keyboard), so in the second screenshot with two apps side by side and the right one in focus, moving the mouse to the menu will result in the active application and menu changing.