It's a very impressive achievement. In 6-8 years or so Lebron'll likely be right there with Kobe and the rest, Durant'll likely climb up the ladder pretty fast as well. Those two certainly have the potential. Lebron's already got almost 21k points under his belt and the way he is playing seems like it's going to be a while before he isn't getting 1900-2200 points a season. But just the same, nothing is guaranteed, and that's part of why this sort of thing is special. Being able to stay healthy and still be productive and to stay in the league and play at a high level, to not suffer injuries you can't come back from(like T.Mac) and to have the right teams, the right conditions in the league overall and just really a little of everything but also to be able to get through having the wrong teams and the wrong conditions in the league.
Lebron's scoring has diminished a bit since joining Miami, obviously enough, he'll be 29 next year but he still plays like he's 23 for the most part. He only needs 4 or 5 more seasons really to hit 30k assuming he doesn't suffer any setbacks or have a drop off in his scoring ability. We've all kind of figured, and a lot of this is just bias against him, but we've all kind of figured that as his athleticism declines his game will decline sharply as well. Unlike Jordan or Kobe, Lebron simply does not have anything near their level of footwork and creativity off the dribble. He plays ridiculously efficiently because he is smart and careful as well as faster and stronger than most, but does that change? does he go from ~27ppg guy to 24ppg then 20ppg in the course of 4 or 5 seasons? Will he be putting up 27ppg when he is 34?
Durant is an even bigger unknown in the sense that he has started his scoring pace a lot faster than just about anyone and realistically there's no good reason why he won't have the scoring title every season for the foreseeable future. But since he's also so much younger there is so many more years ahead of him for something to set that off course. Simply can't make any predictions either way. Obviously if Durant can play 14-16 or so seasons and average 28 or more in most of them he'll end up right near the top, but who is to say?
But this thread is about Kobe and what Kobe has done is a special achievement no matter how you slice it. Not as dominantly as MJ, not as inhumanly as Wilt, not as healthily as Malone or Kareem. But like just about everything else Kobe has done in his career, he did it his way and did so with confidence.