I've always thought that Mos Def is a gimmicky, tedious rapper. Same with Common.
But here's a thing, I am at the end of the day a New York Rap Fan, not a commercial underground fan. NY Rap is different, it takes from multiple tiers... The guys on top, the guys who are not on top but aren't considered underground because they talk about weed money guns, etc. The Mos Def's who are considered vastly underrated and yet sold significant amounts of records and were constant critical darlings despite making songs about nothing. Or the Commons who have been terrible at rapping in a technique/rhythm level since 1992, yet still get eternally regarded for... IDK, doing a concept single??? LL Cool J did concept singles back in 1986??? And then of course, the underground underground with the Melineks, Kool Keith's post-Ultramagnetic career, Doom ofc. and even el-P.
Now, back in the day, there was not a severe disparity. Look at the Stretch & Bobbito show. Stretch Armstrong made a point to keep the Black Robs and the Royce da 5'9s next to whatever nerd rap thing Bobbito Garcia brought in, and they made a balance. The world where Children of the Corn and CNN live in harmony with Company Flow. And stuff like that, the constant exposure is what gets you a Cam'ron. Yeah, Stretch & Bobbito loved to play Myka 9, but they also supported Jay-Z's early career, you get what I'm saying?
For WHATEVER REASON, I have always found the most crassly opportunistic sellout middling "let's make music for college kids" underground rap to be the ones with the biggest chips on their shoulder for doing WHAT??? In what world is The Roots, who chased blatant money opening for stuff like Dave Matthews Band, any less cynical and calculated than anything Puffy did? And as terrible at reciting the stuff written for him as Puffy was, he did think immensely about the content he was putting out, whereas a man like Black Thought has been doing the same bullshit post-Kane freestyle since 1992.
The people who perform 'the culture wars', are always usually antagonists in the mid-tiers of 'commercial underground/underground commercial' who feel insecure about how seemingly insignificant their success commercially and artistically. Its why you have Mos Def thirsting after MF Doom so heavily in that video, HE KNOWS how vastly superior a dude who was a 2nd string Native Tongues after-thought (same as him) has become and no matter how many records Black On Both Sides or Blackstar sold, it means nothing in the long run. Doom is an innovator and a true creative, Mos Def is a fucking clown and has always been trash.