The best part about an airline type seniority list is, you don't have to play Suck Up to Move Up.
In the military it's the only game in town. You want to play that, join the military, and get some kneepads.

Now, to the point that you have no lateral movement in our Airline seniority system, yes, that's always been a problem. I was a proponant of a National Seniority List but you know that it will cost you upward movement as all the other defunkt airline's Captains move in on top of you. As the industry further contracts, it will just take you that much longer to move up at all.

To make it work, we would also need a National Contract, with standardized pay rates, benefits, retirement, etc. all non-negotiable by each individual airline management. They want to buy new airplanes? Fine, here's the pay rate and here's the list of pilots you will be hiring to fly them...

In another life, I flew night freight for Orion. We were contracted pilots for several different cargo ops. One of them was UPS before they got their own flight dept. If you were on the 727 you could bid to fly out of different bases, and in different cargo ops, month to month. One month you could be flying a UPS 727, next month a Purolator Courier 727, next month a Burlinigton Northern 727. All the pay and work rules were the same, as we were actually flying for Orion.

I often thought that ALPA should have done the same thing with the Major Airlines back when the industry was de-regulated. You would apply to ALPA, pay them to train you, get a seniority number and date of hire, then you fly what ever you can hold, out of what ever base you like, nation wide. ALPA would take care of the training, and the contracts. Then, as start-up airlines came and went, you could bid to fly their stuff, or not, but you would have lateral movement and more job security, oh, and a retirement...