Overrated? Now that's hard to say unless there's a clear definition. Rock's only knock is that he only spend a legit 3-4 years a full time, top level, main-event draw. His peak was sky high but very short and during the same time, he was eclipsed by SCSA. No one has ever said the Rock has the largest moveset nor the highest workrate. But he was solid in the ring but his charisma and electric energy captivated the audience like few others and that helped put his work, his moves over big time.
With that said, it's extremely hard to call Rock overrated by any stretch of the imagination, very much like Hogan as few, if any, are saying the Rock is the best in-ring wrestler of all time. As an overall wrestler, total package of a wrestler, he's pretty much as good as it gets.