LeBron is still averaging 28 9 and 8 guys
It's a matter of the pieces working or not. At this point in his career he obviously has no patience for a learning curve. I get it but at the same time he went to the wrong situation then.
He's still getting his numbers because he's a great player who is also smart and knows how to play.
But offense, especially in the first 3 quarters is the easy part. The problem is that he's not in shape and can't close games, he also doesn't have the same explosiveness as he did before the injury.
As for defense, he has mostly rested on defense for years, but has always been able to turn it up a bit late in the season and in the playoffs. Since he came back, he hasn't been able to. Partially because he's out of shape and partially because defense is a reactionary position and he doesn't trust his groin yet when a guy makes a quick move that he has to try to match.