And let's not look at the doctor, dentist, chemist, politician, plumber, bank manager, financial planner, fund manager etc, etc for comparison!...there is none!
You're right, none of them have an archaic seniority system that allows managers to turn the screws, consistently driving down terms and conditions, while any of the above would say
you I'm off to get paid what I'm worth or go and live where I want to. They don't have to pay to keep you they just have to pay enough to get you in the door or you pay them to get in the door