As great as any one wide receiver is, there will always be a time that you need another who can make a play. A wide receiver’s production is contingent upon his quarterback being able to get him the ball, and if a defense truly wants to take a star receiver out of the game, they can roll the coverage to him and make it nearly impossible to deliver a safe throw.
The only way to compensate against a defense leaning against a receiver, other than having other available targets, is in diversifying that receiver’s package, opening things up in order to try to prevent or discourage teams from doubling and tripling him.