Qt Widgets does not use native widgets on Win32 (I heard they're called "windows" there). It only spawns a single native window, and performs all input handling

Qt Widgets does not use native widgets on Win32 (I heard they're called "windows" there). It only spawns a single native window, and performs all input handling itself. Qt 5 has a mode (https://doc.qt.io/qt-5/qwidget.html#native-widgets-vs-alien-widgets https://doc.qt.io/qt-5/qwidget.html#native-widgets-vs-alien-...) which uses native Win32 widgets, but they're more like blank canvases drawn by Qt, than actual Win32 push buttons, and still look slightly off. And it reduces performance.