This section of rap isn't doing that crazy right now. Honestly he's doing well for his lane.
The top of this lane in terms of popularity is probably JID, Westside Boogie, Joey Badass, and Vince Staples(1M+ monthly listeners).
He's slightly behind the likes of Symba, LaRussell, and Ray Vaughn who have had more opportunities(they're all in the 200-400k listeners a month range). He's ahead of Anoyd who is similar in terms of rap ability. I'm surprised that he's more popular on Spotify than Ransom and 38 Spesh.