This may be an unpopular opinion, but I think more than anything else in entertainment you can't compare Rap music from era to era. It's such a youthful, immediate medium that serves those that are living that experience at the time. It's the music of the 15-20 year old.
That doesn't mean you can't grow to appreciate others that came (before or) after that time in your life, but you are not going to get the same kind of 'charge' from the music as you did in that time window.
So, it's all equally great to me. Because some 15 year old is having his mind blown by Chance or Tyler (or whoever is considered the new thing now) and they are the one's who ultimately decide for their generation. It's not for the 20-somethings and the 30-somethings to decide.