I have heard people bad mouthing Gates, they say he is over the hill and that his time is limited But try and remember he's also on the back end of his thirties so it's not unreasonable to say he isn't going to preform like he did 5-10 years ago.
I think the reduced role he's taken on this season has probably lowered his sharpness on the field but that is normal.
That said I think he's garnered enough respect to where regardless if he drops a ball here and there we should allow him to play until he can't anymore. He's basically the GOAT #1b so let him do what he wants. When he's gone all we'll be able to do is reminisce. Let's enjoy having him while he's still playing.
I'd honestly bet that he was more than happy to take a reduced role. He seems happy to mentor and that is a strength that any good team needs to stay healthy. The Chargers will always be a better team when they have seasoned players like Antonio in a mentoring role, he has been there. He is like a general if he doesn't get spooked he will keep the younger players from getting spooked. It is just the nautral way of things.