What I meant by that is that GMs are far better off giving more money to younger promising players than they are to overpaying for aging players who are going to be significantly overpayed as they drop off. Ideally, you'd want a player's long-term contract to cover ages ~22-23 to ages ~28-29. And then give less money to older players by taking into account they will most likely regress.
I think everything will naturally adjusts towards that now that younger players get bigger contracts.
And 28 years old is, for most players, NOT the middle of their prime, but more towards the end. Exception exists, obviously.