You can't just go of one metric like length of career
Fabolous is as popular as Eminem in that case, Drake as The Beatles, Asap Rocky as BIG.
Drake has been the #1 or #2 rapper for 7 straight years like top 5 artist in any genre, not just on average but every single year. I mean you've really got to hate dude if you are even trying to argue about this.
So u really gonna put Nas' 20 years up against Drakes 7 years huh??
If Drake falls off in 2 years then Nas will overlap in popularity by default just off his current rep alone.....
That Fab/Em comparison was terrible by the way....for one Em came first and was around during Fabs prime, unlike Drake with Nas.