There is a very interesting video on how carbon brakes work.
And as a320 fctm states, the pilot has to reduce the number of brake applications in order to reduce brake wear. The wear is not dependent upon the pressure or time brakes are used.
Therefore, I believe autobraking system generally reduces wear, since you are using the brakes just once. And if you vacate at the last taxiway, you will probably use your brakes many times until your parking stand, thus increasing your wear.
Maybe those are the reasons why operational procedures recommend routine use of the autobrakes.