Kobe was pretty much exactly the same player the year he lost to Celtics versus the year he beat the Magic. Here's his numbers from 08 versus 09 in the playoffs:
2008 Kobe (21 games): 30.1 pts, 5.7 reb, 5.6 ast, 3.3 TO, 22.0 FGA, 9.2 FTA, 47.9 FG%, 81 FT%, 30 3FG%, 41.1 MPG.
2009 Kobe (23 games): 30.2 pts, 5.3 reb, 5.5 ast, 2.6 TO, 23.0 FGA, 8.6 FTA, 45.7 FG%, 88 FT%, 35 3FG%, 40.9 MPG.
Suddenly because he won the media pumps up the story that he matured or some bull . Now if a player drastically changes his numbers or plays in some way differently and that is why the team wins you could make a case but Lebron's numbers were already plenty good enough to lead a team to a le in 2008-09.