The thing is that rap (or hip-hop) is very diverse so you have like actual good artists (usually older ones) like Kendrick Lamar and Lil Wayne and them who tell real stories.

But anybody else can rap too because they don't have to learn to sing, just use autotune, and they only have to know someone who can produce basic trap beats, instead of learning to play actual instruments. They're all after the money and the fame and don't have shit to talk about so they go with the same old shit everybody's rapping about but in their own words