I could not agree more, but apart from not winning anything , and quite rightly as you have said, Kane has been there and got the tshirt, so he is hardly a fresh young thing.Motivation of individuals. The league is a 38 game slog interdispersed with Cup and international games makes it very demanding for individuals both physically and mentally.
Expecting players to maintain hunger and motivation season after season is imo unrealistic, so bringing in fresh, hungry players is good for the club to keep advancing.
Again a reason I am not convinced about Kane is the hunger, I am not utterly convinced about that, although with Grealish I would agree if he wants to leave Villa and joins us , that would be a good sign.