Mainstream rap is definitely for the youth. They decide what’s popular.I hate when ppl say hip hop is for the youth. In its infancy it obviously was, but now you got a few generations in this thing. The older generation of rappers have made legit careers out of hip-hop. There were not 40 yr old rappers in the 80s, 90s and early 2000s. But now there are so the culture needs to shift away from that hip-hop being for the youth, it's not anymore.
This isn’t exclusive to rap. It’s all of pop culture