Native is a funny word. Some devs think it's about going as low level as possible. I think it's about connecting as close to the target environment as possible: A native Linux app using GTK is only native on Gnome. A QT app is only truly native on KDE. A native Android app uses Java or Kotlon. A native iOS app uses Swift. A native Windows app must use Win UI. A native MacOS app uses Metal, on windows it uses DirectX.

Being native means perfectly matching the expectation of the platform without roundabout ways to do things or missing UI features. It goes beyond performance. It's about reusing the platform defaults as much as possible.