The biggest thing i am encountering in making Hip Hop since Hip Hop has been reaching the pop charts. These pop chart artist build the character matrix for alot of up and coming artist. So they mimic these artist just to satisfy an audience. This always been a problem in music making when you copy artist to gain gigs. Ray Charles was famous for imitating styles and mimicking other artist voice because those artist were their favorite at the time. Artist will sound exactly enough when in the course of making records. Only in making records you will fine these common patterns.
Pop music will add the pressure to younger minds to enforce that this is the artist you will design yourself after. Idolize to the point you can hear their character make in their voice. Childish Gambino is one and it seem like he controlled it enough to knock out his first album. While other artist whom used this approach were one trick ponies. Kendrick Lamar definitely is one these that was mimicking Kanye West before
signed with Aftermath. Why he was passed by other labels.
Almost all major label are mimicking other artist either signed or unsigned.