Just to be clear, mainstream rap straight up doesn't exist anymore so theres no point in arguing if yesterdays rap was better or overhyped. They got rid of all things rap, r&b country, punk and rock in the late 90's.
They then took pop and expanded it into those genres by adding the lil gimmicks each genre has.
Look this pop singer is wearing a cowboy hat and mentions a farm, it's country. Check out this pop singer wearing skater clothes and mentions her dislike for authority figures, welcome to the new punk. If the pop singer sings about how much money they have then its rap. If the same singer with the same beat talks about getting laid then its R & B.
You can take any pop singer like justin timberlake and britney spears, throw a change of clothes on them and the subject matter of a song and you got yourself timbaland and taylor swift. Another change of clothes and a backup band and they got themselves nickelback and avril lavigne. Honestly the only genres that haven't been taken over by pop is classical music and fuckin speed metal.
point being:
IF ITS MAINSTREAM MUSIC THAN ITS POP MUSIC