We have discussed seniority before. In my view, it only works for a handful of pilots at the top and the companies and managers. It is a cage that prevents movement of workers from bad companies to good and permits poor management cultures and poor terms and conditions because pilots with a small amount of seniority are reluctant to start again.
Take a look at medicine, the maritime industry, engineering, law, finance, education or any other profession, and you will see it does not exist there. Seniority lists are peculiar to pilots and actually break a lot of employment laws. Why we continue with them is simple - airline managers love them and the unions permit them because the councils are usually filled with senior pilots.