Your Galaxy S III or Nexus 7 is not a museum piece yet. With the correct APK, it remains a fully functional YouTube machine.
Google officially ended support for Android 4.1.2 Jelly Bean in mid-2021. The last compatible version of YouTube for this OS was . Youtube Apk For Android 4.1.2
If you have a broken or partial version installed: Your Galaxy S III or Nexus 7 is not a museum piece yet