I really don't like to see that Lebron James has to carry the team to victories most of the time. He should already have left those days behind from now on. And as far as I know, he doesn't want to continue to do this too. He wants his team to build a team which consist highly capable players to take the load off of his shoulders. But Lakers did the opposite for this season. And last night, we saw another example that Lebron carried the team. Lakers just can't go on like this to the end. They could have big problems in the playoff stage.
It's worth noting that Lebron has become more injury-prone in the last few years. So you're right that the Lakers should reduce the load on him, and his teammates should be more effective on the court if they really want to compete for the title. By the way, Lebron scores an average of 28.7 points per game this season. I would even say that he is showing the best performance in the last few seasons, considering that the last time he scored an average of more than 28 points per game in the 09/10 season.
But still though, James is still performing above average at his age in NBA. Maybe it was really because he wanted to proved that he can still play in the league even if he is nearing 40's. So he is carrying much of the load and hopefully the support will also be consistent so that at times he doesn't need to put extra mile just to bring the team a W and force his body to grind every game.