What Eminem did was bring the deeper Singles to the mainstream but make them succesful make those real life type Singles get in the top 10 10 or the top 5 or as i said even number 1
Have other Artists had a deep/personal Single that was a succesful Hit? hell yeah but have any other consistantly made deep Singles their whole career which were Smash Hit's? no
What Eminem also did was bring the Singing on Hook's to the mainstream on these deep Song's you had other Artists who made deep Son's spoke about what they been through spoke about what they felt but non that consistantly were Singing on most their Song's like Eminem
Again wether you like the Singing is preferance but look at the Song's and were they were in the Chart how big Hit's they were 'Not Afraid' 'Cleaning Out My Closet' 'Mockingbird' 'Beautiful' etc all very succesful
Were as you right in saying other Artists have covered the same topics Eminem has but have they had the same story and up bringing he did? Nas made Song's about growing up poor but did he have the whole story like Eminem of a drug addict mother, being homeless, being the only minority in a predominantly black hood, growing up with no father etc it's not just what Eminem says but it's the whole story as well of his life
like 2pac is deep but he more deep from a political point of view while Eminem is deep as far as he Writes about everything he directly experienced in his child hood and life 2pac is more of a what i seen what my homie done type of Writer were as Eminem is very autobiographical you learn everything about Eminem's entire life from his Music you learn about his family, his personal day to day struggles etc