I wouldn't say he was overrated. In recent seasons he's been much diminished as a player, but in his prime he was outstanding. He carried a lot of decidedly average players at Liverpool over the years, scored countless wonder goals, and often dominated the entire flow of matches. It seemed to be his will alone that won Liverpool some memorable matches including the Champions League final victory (although I'd argue it was Didi Hamann whose presence swung it in the second half of that match tactically).