I think he has the potential, he doubled his numbers thanks to Moncrief's injury but still did not completely step up in his absence the way you'd want a first round pick too. Kelvin Benjamin was picked around the same time the year before and had a stronger start to his career although injuries, both his and Cam's, have hurt him lately. Guys like Jordan Matthews, Davante Adams, Allen Robinson, and Jarvis Landry who were second round picks the year before have all been outperforming him as well.
I'm actually comparing the 2014 and 2015 WR drafts in the first couple rounds. 2014 also had Watkins, Evans, OBJ, and Cooks in the first round as well vs. 2015 which had Cooper, Kevin White, Davante Parker, Nelson Agholor, and Brashad Perriman all before Dorsett. 2014 was a monster year.