I felt Cousins dominated at an increasing rate towards the end of this past season. He's still learning and adjusting to the NBA game. He didn't become the focal point of the offense until maybe halfway through the season.
Cuz has had to deal with a few things so far in his NBA career. First, he had a coach throw him under the bus. That set him back some. Secondly, he's in it bad with the refs. He had foul issues, but now he has ref issues. He gets no ref love and it limits his minutes. Third, he's been playing without a real PG for most of his NBA time. It's been a lot of solo-work for him to get shots, up until IT rose up to get him easier looks. For the first quarter of the season, most of Cousins' shots were from gobbling up the rebounds from the junkthe rest of the team was putting up. Then he'd get tired of being the putback machine, ignore the team offense and go one on one. Like most of the team, he wasn't a part of an offensive system and would go freestyle when frustration hit. This didn't really teach him anything about how to do his best in the NBA game.
Then Westphal was fired, IT got more minutes, Smart slowly had a tidbit of a real offense emerge, and Clifford Ray was hired.
He's overcome all of those things to go from "maybe zach randolph" to "potentially the top big man" in discussions.