There are two sorts of people: those who want it now, and those who are prepared to make sacrifices to get something better later.
If you want it now, BA with its seniority driven system is not the place for you.
If you are happy to work your way up the system and stick with it, BA is still pretty hard to beat when you get the seniority in.
We had exactly the same discussions in BA many decades ago, when people hopped off to get early commands, then found themselves without jobs.
Those who stuck it out in BA mostly felt in the end they had had by far the better overall deal.