Earlier in his career, until around the time of his MVP win (before all the injuries), Durant was on course to break Kareems record one day. You could also argue that without all his injuries, he maybe would be an even better player today, would maybe averaging even more PPG now in his mid-30s than he already does.
Did the injuries of KD allow Lebron to be the all-time points leader for years to come?
I mean tbh LeBron entering the NBA straight out of high school also gave him a year worth head start.
Also injuries are part of the game and staying healthy is a skill.
LeBron has always been the leading ball handler and scorer for his teams and Durant joined teams like the Warriors, Nets, and Suns where those duties were more often than not split.
TL;DR If every team change Durant makes stays exactly the same, even if Durant stayed injury-free, no he would not have passed LeBron.
Lebron spends a couple million a year now staying healthy. Durant looks like he eats Skittles for dinner.