It's not about checking nobody. Rap music is about competition and you're only as good as your last record. Mainstream will always be that. nikkas rapping about the same shyt they did in the 80's and 90's. The only difference is the slang and production. Same old excuses. At the end of the day it's just music. People take it how they want it.
I disagree with basically everything you've said in this thread.
First off, rap was a young man's game 15-25+ years ago, because young people were the ones moving the culture forward. I don't mean buying shyt, anybody can buy shyt, I mean old heads being shook the first time they heard a young LL or Rakim. Like

"damn, I need to step my bars up before I'm obsolete".
So yes, definitely, back then it was a young man's game. Now....do you seriously think Chuck D or KRS or whoever is intimidated by the shyt Chief Keef or Young Thug is putting out. They probably listen to it like

"I'm supposed to step aside for this?

fukk outta here"
Half the rappers selling, and that have been selling over the last decade, are in their 30's, or close to it. The only thing young people do nowadays is buy shyt, with the exception of a handful of people.
Fred.