The last version of Nova Launcher that supported Android 4.4.4 was (released back in 2020). Anything newer requires Android 5.0+. That old APK does exist, and the Prime unlocker can still be applied—provided you find a legitimate license.
Apply Material Design elements and custom icon themes to give an old phone a contemporary feel. Recommended Versions for Android 4.4.4 Nova Launcher Prime Apk Android 4.4.4
Modern launchers like Niagara or Hyperion often require Android 8.0 Oreo or higher. They rely on newer APIs (Application Programming Interfaces) that simply do not exist on KitKat. The last version of Nova Launcher that supported Android 4