I think seniority is essential in a role that is that of an operator. In business things are different, one generally has to justify ome's pay with your performance. With some roles, a good decision can directly loose or save thousands, if not, millions. Of course, without six monthly recurrent sim, the politics of seperating the bull****ers from the doers can be problematic.
With flying, our ability and suitability is easily measured, even if one disagrees with the metric. Therefore a merely competant pilot is unlikely improve the company's bottom line measurably more than Mr Situational Awareness. A pilot's lot is that the path is generally laid out for us (SOPs), all we have to do is follow it. Dealing with business related problems is genrally about flexibility (discretion, working on a day off, etc). Managing operational issues, are generally about remaing legal and identifying when plan has to change. This will never be a direct benefit to the business and caution usually costs a lot of beans.
So, in the same role, how can anybody justify a better package, other than loyalty?