Cooper is a proven WR1 if you give him the ball. He is the only WR drafted 1st round in last 5 years who has gone pro bowl. If you want a potential pro bowler, amari is a better option than drafting a WR.
List of WRs drafted in 1st round since 2014: Amari Cooper, Kevin White, DeVante Parker, Breshad Perriman, Nelson Agholor, Phillip Dorsett, Corey Coleman, Will Fuller, Josh Doctson, Laquon Treadwell, Corey Davis, Mike Williams and John Ross.