Does applying the parking brake help with transmission life?

how many people have seen transmissions where the parking pawl has failed?

Fair question. I’ve only seen damage when cars were shifted into park while still at a slight roll. Maybe others have seen additional failure modes and can comment.

But of course. Whenever I use someone else’s stuff, I always try to heed their rules.

Just out of curiosity though, any idea what the cost of fixing a parking pawl versus parking brake is?

Well, I can’t dispute what you have or haven’t seen. I can say that the seven or eight cars that I have had all had/have good working parking brakes that would completely lock the rear wheels. You could drag the car, but the wheels wouldn’t turn. These all had/have either foot activated parking brakes or electric parking brakes. I did drive a car once with the kind of parking brake that you pull up by hand. As I recall, it didn’t hold like mine do.

I agree that many park brakes will not hold a car on a steep hill, espedially uphill. However, mine will.