I don't know, that ridiculous touchdown catch says otherwise.
And for as many people who point out that he's turning 30 as negative, he's also about to hit 10k yards at 30 as well, which is historically elite.
I think he's checked out more than hit the peak. He also plays the type of game that should allow him to last longer than other receivers. He'll probably put up a few more good seasons elsewhere on his way to 15k.