I used to have a 2019 F150 Lariat and the electronic rear locking differential used the rear brakes to actually do the "locking" . It was very common on the F150 forums for owners to report what they considered to be premature wear on the rear rotors and pads (20K miles for example) even though the front rotors and pads were still fine. Since most of the normal braking is done by the front brakes, discovering that the rears are worn out was annoying.