A lot can indeed change, but you fail to mention that Andy Flower is probably bright enough and certainly unsentimental enough to move with the times rather than stubbornly refusing to change and keeping picking the same faces again and again as they grow older - indeed, he has already shown with the one day game that he is looking to incorprorate more youngsters into the national set up so that they gain experience before they are asked upon to be the main men.
Accepted Australia have a crop of good young players coming through - but so do England. As I've said before, for the ones you've named we have Bairstow, Taylor, Stokes, Lyth, Root, Borthwick, Adil Rashid, Rafiq, Woakes, Finn, Ashraf, Roland-Jones, Topley and plenty more who have every bit as much potential.
In summation, the current England team is nowhere near as good as the best Australian side under Waugh, but I doubt that in five/six years time they'll be as bad as the side that Ponting led into the ground either!