Regarding rust on a brake rotor

No longer live in a rust belt state… but this is what my rear rotors looked like off my seldom driven truck. 1/2 the brake pad was left but the rotors were rusted beyond use. Very typical of what I’ve experienced on several of my cars.

The caliper slides were seized as well. I replaced all 4 calipers, rotors, and brackets to bring it back to having good stopping ability again.