Alot of Drake fans today don't remember despite selling records, Drake still felt pressure from older rappers ahead of him. Jay-Z, Kanye, Gucci, Wayne, etc they were still the top rappers. Drake needed new talent to collaborate with so he sought after young underground artists. Kendrick was already up and coming because of Overly Dedicated and Section 80, getting signed by Dre, and having J. Cole as a producer. Hip-Hop blogs were already declaring him the next West Coast savior. Not only Kendrick was a good rapper, Drake wanted a piece of his clout. With Kendrick doing features with Drake, they both benefit.
Same can be said with Migos, Rocky, and even The Weeknd for obvious reasons.
