The QtWidgets QToolBar class doesn't always look and feel native, which led to e.g. the birth of QMacToolBar.  As a cross platform toolkit, Qt should strive to look and feel native, and do so as an implementation detail, so that the user can deal with a cross platform API. It would be great if QToolBar had similar logic as e.g. the file dialogs, where we use native controls/APIs if we can, and then fall back to the generic toolbar if the user uses features that the native controls can't represent.