2/4 songs had good beats, the other 2 not so much. But production is subjective, so let's get off that topic because it doesn't prove anything. You're the only one who'll say Nas had better beats than Cube throughout the discographies.
Yeah there are some West Coast MCs that are more complex but for the most part it isn't in most artists' DNA on that side. Plus as I said that isn't his purpose. Cube has done some slick rapping stuff before like on The Bomb or The Grand Finale (DOC's song). Complexity does not necessarily factor into how good a lyricist one is. Chuck D was never super technical. Scarface was never super technical. You gonna call them lesser lyricists because of it?
The Predator is more of a classic than Stillmatic and any Nas album not named Illmatic. Hell even IWW has been debated at times. At least Cube has 2 UNQUESTIONABLE classics.
Nas or HOV (especially Reasonable Doubt HOV) or Prodigy or whoever may appear more lyrical because they are more poetically-astute, which means their expression involves capitalising upon many rhetorical devices and poetic techniques. But in the balance between lyricism and technicality, that makes them better technicians in rap, not necessarily lyricists.
When something as deeply artistic for evoking emotion exists, as it does in Cube's raps, you cannot call him an inferior lyricist. He's one of the greatest.