To be fair, Lebron just turned 37. He still has plenty of life left in the legs. Ha.
Lebron is tied with Embiid 0.2 ppg behind Durant for the league lead in ppg. He is tied for 10th in spg, 17th in apg, 20th in bpg, and 35th in rpg. No other player in the entire league is in the top 35 for all 5 categories and only Jokic and Harden (barely) are in the top 50 in all 5. Lebron is also tied with Tatum for 4th in mpg.
You don't go performing at that level to being a role player over night without a major injury. Now Lebron is clearly going to get banged up more often and take more time to recover, that comes with age, but we've seen very little on the floor to indicate he isn't still a top 5 player in the world right now. Nor have we seen anything that would indicate that he won't still perform at a high level for the next couple of seasons. At least when he is healthy enough to play. That is of course the rub. How healthy is Lebron going to be? No one can predict that, but he'd absolutely be worth the gamble for any team with championship designs over the next couple of seasons, which is why the Lakers would never trade him even if he was open to it. And that is on the court, let alone of the off the court stuff he brings as well as how close he is to Kareem's regular season points record. The jersey he is in when he breaks that record will forever be known and is great free marketing.