I think Drake could take a step back but the fact remains that his next album will do 350k+ and live on the charts. I think Cole took damage too but will still hit 300k+ first week. Carti still sells, Uzi still sells, Lil Baby can sell, Durk too, etc. There are a lot of successful rappers, sales wise. It's not just Travis and Kendrick.
If there's a problem it's that rappers after Drake/Cole/Kendrick haven't grown the way they should. Both Carti and Uzi's last albums were poorly received by many fans, as was Baby's last album. If you read the HDD article it details what Travis' team was doing behind the scenes to get him to #1. What is Uzi's team doing right now? Carti? Baby? Lot of dudes are just burning braincells on drugs and endless studio nights recording the same shyt over and over. And their teams aren't doing shyt about it.