Great point, and exactly how I feel. He needs to get in the gym and shoot hundreds of jumpers daily, and also work with his coaches to improve his fundamentals and other parts of his game. His game as of right now is to shoot a jumper or bulldoze to the rim. And that is why good team defense shuts him down like you said.
I feel like because he's so much stronger/athletic than everybody else he feels he doesn't have to work so hard. He's already great but if he wants to become legendary he has a lot of work to do. He should take notes from guys like Kobe, Duncan, Dirk etc. Those guys bust their asses in the gym, Lebron has to do the same.