Huge difference in pace, so LeBron scored on higher volume and that explains lower efficiency.
I don't see how pace matters here since LeBron had much higher usage to make up for the lower pace. it's not like Kareem couldn't score every time down the floor, the problem was that his guards were so bad that they often couldn't get the ball past the halfcourt.
Also James had to create more for himself, while KAJ partly relied on what others created for him.
on whom exactly was Kareem relying that year ? Ford ? Tatum ? Cazzie Russell ?
LeBron had a lot more help offensively. at least his teammates provided spacing and LeBron wasn't getting double teamed every time he touched the ball. Kareem didn't have the best shooters in the league to make his life easier. Mo Williams was a decent player, a guy like that could push LA over the top in '77.