It was not his age that was the problem. If you bother to scratch the surface, there are three key issues:
(A.) He's inconsistent. This is obvious if you look at his form and it's the reason he was given last year by Helmut Marko as to why Daniel was preferred over him. With Dan alongside him he would often make mistakes under pressure, particularly in quali. His resilience was questionable.
(B.) His feedback is not good. See this quote from ex STR designer Furbato: "The other driver (Jean-Eric Vergne) was very limited in his feedback, so Daniel was always the point of reference."
http://www.grandprix...ns/ns28804.html
(C.) Brundle mentioned today that Marko had said JEV was let go because of what he wasn't doing out of the car, implying he did not have the required work ethic.
On his day he is brilliant, as good and sometimes better than Dan (esp in the wet) but those three things above are very important parts of being the complete package. Can he change them? Sure. But F1 is not a very patient sport. Personally I think there's no question he is outperforming Kyvat this season, but he is a lot more experienced, so...tough call.
Edited by goingthedistance, 04 October 2014 - 18:13.