Karl Malone might be Lebron's closest comparison between size, athleticism, and longevity. He was a legit all-star until he was 39. Lebron probably has a solid 5 to 7 years left as a top tier player.
Yep. They are physically very similar. I'm not sure Lebron has that many years left as a top tier player though as he did enter the league a lot younger than Malone. Malone was 35, 14 seasons in, Lebron is 32. Plus Lebron played a lot more post season games and Team USA games than Malone did through those 14 seasons (though Malone did play more regular season games). I fully expect best in the world Lebron for another season or two, then expect to see the decline, and I'd be surprised so see Lebron as a top tier player 20 seasons into his career. Still effective, sure, but all star level, likely not. But Love and Irving will still be in their prime then, so if the Cavs can somehow stay together that long, I could see them still be a real legit contender.