idk man
for one I think viewing especially viewing disco rap thru the lens of later rap/rap as a whole is incorrect or at least incomplete it's at least as much if not more in the context post-disco/pre-house, uptown/downtown New York. the simplicity of the rapping makes much better sense in that context. like Debbie Harry in Rapture isn't a million miles away from contemporary rap proper. this is more true the further back you go and ya Run-DMC/Def Jam is kinda year zero for rap as its own thing (even if the Simmons brothers got their start in the disco rap era).
and there is a certain naivete, lack of self-awareness that persists even into the late 80s, maybe the early 90s. The Chronic is a good transitional moment to pick b/c even tho it was innovative/new it's also referring back to N.W.A. etc in a way that rap mostly hadn't done up to that point. You get the same thing in 80s hardcore (the punk kind), when the youth crew bands in 88 are consciously referring back to Minor Threat in a way no one had previously done in hardcore.
as far as boom bap, both the original drum machine and the later early sampling varieties, I think the stripped down nature is a huge strength.
