The benefit of trading for a #1 receiver (AJ Green, Stefon Diggs comes to mind) is not only their potential, but also now we have much better match ups.
For example: John Brown always attracts their #1 corner. The other team's Tre'Davious White, if you will.
Now John Brown gets their Levi Wallace or Taron Johnson (#2 corner).
Cole Beasley and Duke Williams gets their 3rd and 4th best corner.
We will be a matchup nightmare. We don't need to throw it to AJ Green every play, but they have to cover him. And often it will be with two people.