Look what happen to his past teams he need to recruit a lot of star players before he get the championship that he wants. But Lebron is undeniably a true legend since despite of his age right now we can still see him carrying his team. Also by looking at his performance his still capable to play more games since its like we don't see a decline of performance from him. He keep becoming more consistent each year pass.
Lebron had to face them at Cavs almost every year during that time, but at finals, if he was at Lakers, he would have to face them at conference finals or earlier, so it is not going to be easy to beat them there neither. Moreover, we had great Rockets team, great OKC as well until Durant left to join warriors, so Lebron would had even more teams to battle as well. I do not agree that Lebron would have done better at Lakers, I think he was great at Cavs.