Perhaps the inequality / asymmetric braking problems originate from the lack of manual practice
What manual practise are we talking about here, Maximum effort stopping or everyday landings?
At my home base I use Autobrake 3 for the vast majority of landings but I still get lots of practise at manual braking to make the preferred turnoff (avoiding backtrack and distressing the guy behind).In my airline the FO would not get much practise because only the Captain has a tiller and generally takes over as we get below 60kts.
As for max effort well I can't practise that with pax and in the sim we want to encourage leaving RTO engaged.
This discussion is of course very type dependent but for modern Boeings/Airbus types Autobrake is a great piece of kit. There are many areas where practising would improve (occasionally required)performance but in reality it's not possible or not sensible.