Was/is Elvis a bit over rated?

Okay Okay I realise some of you will think this is a controversial question but hear me out. So okay here we have this guy who had a great voice and lots of charisma but why is that enough to make him such a legend. He only knew 3 chords on a guitar and never wrote a single song or tune in his life. And he starred in some pretty dire movies although that was mostly his manager's fault. Can you see what I'm getting at? I do like most of his stuff but I sometimes think what's all the fuss about.....