At least due to the fact that LeBron had the time advantage because he started his career at age 18, while future players must be at least 19 years old to enter the NBA draft.
Regardless of the age when Lebron enters the NBA draft, if compare to Kareem, the basis should be the number of seasons and games played. There's no time advantage or anything related to that.
Kareem played for 21 seasons with 1560 games.
Lebron is currently playing on his season 20 with 1407 games so far.
Lebron will be able to pass Kareem's total scoring points in 2 to 3 games.
I agree with you though that we might not see someone will break that record for at least 1-2 decades.
Yes, might be another decade or two for someone to break that record, Vince Carter played for like 22 seasons in the NBA but never got close to that scoring record. So it's a lot of factors, combination of them to be great to even get into the top 5 all time.
And now Lebron will be on top and no one can even, no active players. Maybe someone will break it, but it might take 20 or even 30 years even if the scoring average will increase.