There have been a lot of people critical of Landry, or less than enamored with Landry, for a while now. Even though I think his personal foul antics are certainly worth considering, let's put those aside for the moment and look solely at his play as a receiver during the whistle.
I think he's a good player, but I'm very open to the idea that Miami could allocate the cap resources the team would spend on Landry to another position on the team, and then see what Grant or Carroo -- or a draft pick -- could do in the slot. For instance, if you told me right now that we would draft Braxton Berrios (and note: I am not a UM fan), I'd say "Good luck, Jarvis." Why? Because I think that player can run the same routes we ask Landry to run, and we probably won't lose much effectiveness, and he's projected as a 4th(?) round draft pick.
So no, I don't feel that the role he plays is irreplaceable, or even close to it. Good player? Yes. Worth 12+ million dollars annually against our cap as a guy who runs crossers, flares, and screens? No!