I think he's become James Harden-like now, but I think Harden might have actually eclipsed him. Might be a bit sacrilegious to say, but Harden generates way more points this season and IMO has been a better defender. He's actually one of the league leaders in steals, and locks in a lot when he's switched onto bigs in the post.
LBJ on the other hand is straight up garbage on defence, and can't seem to simply will teams to victory anymore. His injury accelerated his decline I think