I replaced the shift cable twice in our previous truck, a dodge Dakota. a mechanic suggested that it was due to excessive force required to get the truck out of park on a sloping driveway. now we use the parking brake on our new 1500 dodge ALL the time. im pretty sure the new electronic shifter system is quite a bit more pricey to repair than the Dakota's cable, the 1500 has the 8 speed with rotary knob(which we love!)
he also said to engage the parking brake while in neutral, let the truck roll in neutral that 1/2 inch or so to take up slack in the braking system and then put it in park. makes perfect sense to me and that's what we do
"use it or loose it" is very true, personal experience with several vehicles proves it to me
keep in mind too that park doesn't work well if you're parked on a slippery surface. one time many years ago we parked on an icy steep driveway in park only. the truck rolled down the icy driveway in seconds, I put the truck back up and used the parking brake, it engages both rear wheels, it stayed there
I just wished they put parking brakes on trailers, manually applied at the tongue, the parts are available from dexter and they should be mandatory