Playing for longer doesn't make someone better. Talk about rebounds, sure Bron plays forward and sometimes even C, of course it'll happen.
Kobe was a significantly better defender than Lebron James with comparable and even better offensive production in his prime. Kobe took HIS team to multiple champions, he didn't quite multiple times and recruit multiple hall of famers for a free ride through the playoffs.
Lebron is more athletic and faster of course, better rebounder due to his position. Kobe is the closest thing to MJ we have ever seen.
Lebrons prime has lasted much longer obviously which is impressive, but if we're talking who was the better player, give me Kobe all day.