Autobrakes are great but brilliant in crosswinds/asymmetric landings. I don't know about others but I'd find it very hard to get consistent manual braking with large rudder inputs using toe brakes... You're trying to produce two identical and steady forces on your toes combined with two different and changing ones on each leg - no mean feat! With the autobrake you just have to steer.
Airbus,
exactly the same.
Also -
reading between the lines of the Airbus QRH - manual braking is only a requirment when "Maximum Performance Braking" is required (QRH 4.04 Notes).
Finally, as "Dan" states...
...Autobrake leads to less wear on carbon brakes...