I think he is right, but it's the simple fact that hip-hop isn't about telling a story anymore. The Kendricks and the J Coles of the world have a story to tell and do so through their music. As hip-hop has progressed, it went from telling a story (Mind Playing Tricks on me by the Geto Boys is a good example), to catchy pun lines (Lil Wayne type rappers), to beats carrying the artists. If a question was asked if, overall, the skill of rappers has declined over the years I would say hell yes, but it's not about the rapper anymore. Half of these artists would be nowhere if we didn't have the metro boomins of the world. In reality they saved a dying genre of music. Most lyricists are underground artists and the artists that use trap style beats are in the spotlight as of now. I like to use Wiz as a good example of this because he used to use a lot of slow beats to go with his weed theme, but he just hasn't been able to adapt. His last huge hit was 'We Dem Boyz' and it had no lyricism at all and was extremely popular due to the beat. Artists will give people what they want because that is where the money is a everyone wants a piece of the action.