There's no question who's the better receiver. Antonio Brown has earned the title of "the best" and will continue to be one of the game's most impactful weapons. But there are other factors that go in to who's season turns out better.
JuJu has the quarterback, receivers and running game. James Conner has only looked better, Benny Snell Jr. adds more explosiveness. Ben Roethlisberger is a future Hall of Famer while Derrick Carr remains a question mark in the NFL.
A strong statistical season doesn't come with one player. It's a team sport with different players contributing to one's success. AB has the talent, without question, but Smith-Schuster has the package. In the NFL, it'll lead to more success.