I don't know if Lebron is overrated since he has had so much success over a long period of time with incredible stats. However, one narrative has always bothered my about Lebron and that is that he elevates his teammates; I just think that is totally untrue.
While he is clearly a leader on the court and one of the best 'Point Forwards' ever, I actually generally think other players decline when they play with Lebron (and improve when they leave). If you take this current version of the Cavs. Hill, Clarkson, Hood, and Nance Jr were all clearly better players before coming to CLE. Love put up bigger stats with Minny, but the team was also horrible so of course his numbers were going to take a hit. Korver has had some success, but I think it's because his role as a catch and shoot 3-point shooter is perfect in a Lebron system.
It's not that Lebron can't control a game - clearly he can - but unless you're a player with the ultimate confidence (see JR Smith), you can never really have success on a Lebron team if any part of your game depends on making moves with the ball - you just won't ever have that opportunity. He'll trust a player like Kyrie to take over part of the game, but everybody else just walks around on eggshells wondering when the time will come that he will yell at them.
Counterpoint: I somehow still know the name Daniel Gibson.
I think LeBron James - similar to Allen Iverson or Tyreke Evans - is excellent at elevating the play of spot up shooters (Gibson, Korver, Big Z) and rim shooters (Varejao, Tristan Thompson). Finishers. Players who cannot create much for themselves but are great at playing off the ball and hitting open shots that are created for them by someone else (LeBron).
I don't think LeBron - similar to Iverson or Tyreke - is as good playing next to creators. Guys who need the ball and can create for themselves and/or others. Guys like D-Wade & Bosh or Kyrie and K-Love. He doesn't get the most out of those guys. Those players struggle to get enough touches in the right spots in the flow of the offense. It often becomes a his turn / my turn type of setup instead of true teamwork. LeBron struggled with both Bosh and K-Love offensively. He struggled with slashers like Larry Hughes too.
LeBron is great at dominating the ball and elevating the play of role players.
I don't think he is great at sharing the ball with other scorers/creators.
Again -- similar to Iverson or a Tyreke Evans