Any sense of high-mindedness on the part of Ka is fair point. He definitely has a penchant for digging out particularly 'arty' sample picks that give his music a sense of gravitas, but that's what he's going for. You have to remember, him and Marci aren't YOUNG guys by any stretch of the imagination. The UN was a group Roc had been in, but he'd been rapping since the late 80s early 90s as a teen, so if anything that makes him closer to Nas' age than anything.
Luka def. got close to something when he pointed to the 'vitality' of the music; it lacks the energy and propulsion of even your trad underground hip-hop of the modern day. My father listened to the new Prhyme (Premier and Royce) album recently and was bored to tears, calling it "Professional Hip-Hop". The trenchant nature in something like Marc's work is usually dependent on the fact that its made by a guy who wants to capture the feeling of making the rap of that era, but without any sense of trying to escape what the music should sound like for a guy of his age, and for the New York that doesn't exist while being observant of the fact that it doesn't exist.
Something like "Marcberg" is very much an album about time starting to exile you, and I can personally testify that Hempstead (which was right next to where my grandmother used to live) is such a dying community that despite being a bit of a commercial sub-urb (its got a LOT of office buildings taking up most of the property, so if its not huge apartment complexes or housing communities, its buildings that are half rented that you can't even enter taking up stretches of blocks) its just impossible to truly live in. Trying to make music with a romantic feel like Joey Badass does for Brooklyn (which is already such a lie because he goes to a school for the dramatic arts and his family is rich, like, why are you going to pretend to make Nas songs when you simply did not live the life of Nas, who didn't even live the life of his records but knew it was happening close to him) would be disingenuous, so Ka's version where he's remembering the time that's no longer there and reflective on how its lingering for him, that is a much more healthy take.
Its why its the only East Coast Rap I've made in a while besides GS9 (Bobby Shmurda & Rowdy Rebel) or Manolo Rose. They sound like kids trying to make songs for their city in the terms they've inherited from years and years of growing up on NYC's hits. But Ka/Marci also sound like how I kind of feel a certain grown man approach to rap should sound if you've had the sense of career strain that they've had.
Luka; did you also check the A.G. (Showbiz and A.G., not this A.G. Da Coroner dude) album he did where he was really influenced by Roc at this time? Its interesting solely for the fact that its such a pre-established Backpack Icon playing with those tropes.