Indeed, but with some exceptions. .NET SWF shipped with extremely kludgy drawn clones of toolbars and menu bars instead of using the native ones (although the native ones were later exposed) and the result is that those particular controls on SWF apps did not age gracefully (DPI problems, system theme mismatch, scroll acceleration issues, etc). That’s the kind of thing Qt would also face with drawn components skinned to look like the real deal.