Considering that they've been made into musical deities, yes, they are overrated. They were just a rock n roll band, after all. But they are still one of the best rock bands that ever was. How they squeezed all those songs into just a 7 year run is incredible. And the way the sound evolved was pretty astounding too.
Without each other, their musical limitations were exposed, though. With each other, they had undeniable chemistry and a ton of tunes that for whatever reason, mean a lot to millions of people.