In over 20 years, I never ever saw the hand brake shoes on any of my Senators or Omega
I put it down to infrequent use
You would see them when you change your rear discs.
They only do any serious retardation during MOT tests or in an emergency. The reason we strip them down is the actuator, depicted above, rusts and seizes up, destroying the 4:1 mechanical advantage.
The forum guide recommends stripping the handbrake down every 2 years; I doubt many members do that. Haynes says you need to remove the hub and bearing to replace the brake shoes; forum members don't do that either.
I do it when the handbrake needs a mighty heave to hold the car on a hill; that's a sure sign the actuator has seized. It's not a trivial job, but one I find most satisfying.