They're both rappers and producers. Both, complete, hands-on, all-in artists... And - Kanye is no doubt considered one of thee greatest (and to many thee) producers of all-time. But is often passed-up and snubbed as a lyricist / rapper.
Even though he's not a top lyricist rapper, he's well above average when on-point and easily deserving of a mention. And, better than many mainstream rappers who do nothing but rap.
Similarly (but in reverse) - Eminem is no doubt considered one of thee greatest (and to many thee) rappers / lyricists of all-time. But is often passed-up and snubbed as a producer. Where when you look at him on his A-Game - The Eminem Show and 8 Mile - He's incredible.
It's almost like their main field is what they're known for so people feel as if they shouldn't be as good in the other so always say they're not lmao. But I think if Kanye wasn't known at all as a producer, he would be more respected as a rapper. And visa versa for Em.
Imagine if Em wasn't known at all as a rapper but was just a producer and you heard "The Way I Am" or "Square Dance". Or "Renegade" or "8 Mile Road". You'd be like WOW who the fuck is that. They're so distinctive and unique. But it's just because it's paired with his rapping, which he's known for that it's taken for granted.
