Many manufacturers have changed the operation of brakes so that the rears activate before the fronts, especially during light braking - this is to cause even wear.

This has caused problems for people who do not keep up on periodic service - the old conventional wisdom that two sets of front pads will get worn out before rear pads no longer applies,

Also, in some of todays cars, the rotors wear out as soon as the pads.

BTW - this is how F1 cars work - in fact, the rotors wear out BEFORE the pads - this is because of the rotors being able to shed more heat than the pads and also heat more consistently.