If you want to earn like a 30 year old British Airways Captain you need to enter British Airways, became Captain, pass all the checks and wait 30 years.
Seniority is for big boys that like to play with rules.
Big companies have rules. Seniority is part of those big boys rules. Beside that, seniority prevents that some assholes blow some managment dick for a promotion.
Why people dont like to wait for their turn? Why people like to bypass all their senior mates just for a strip??