Good question...... If you listen to the Trad Karate practitioners, then Kata contains everything you need to know ( or everything you need to grade - according to some styles

)
If you listen to the Martial-Arts Historians, then Kata contains what used to be known and taught, and now we have the happy job of to trying to figure out what it all means.
If you listen to the "Freestyle KarateJeetKickKuneFu" guys, then kata is used as a training tool but no applications are taught.
I think this needs Micks input......