Its not quite as simple as that - wished it was. When seniority was brought in to bid for cabin positions in the 80's, it was the right decsion at the time. As time has passed, its become a milestone around Cabin services necks. Remember, this was agreed between both BA and the unions 'at the time'. The irony is that now, seniority only works for 10-15% of crew max. They get what they want 90% of the time, but for the others ? The 10-20% at the bottom get pushed into what the rest dont want at the time eg. product/crewing level changes, pax loads on the day etc. Inevitably where you need the experience, most times you finish up with the inexperience
So both the crew in that cabin and more importantly the customers lose out. Brillient isn't it. As I said, on certain occasions I've swapped crew around but on a normal day, no way. Oh yes I've got balls, but CSD on longhaul I found to be the loneliest job in BA, so I'm not going to cut my own nose off thanks. I personally think seniority should go, as it gives us a hierachal system that benefits just a small minority. Hopefully its something BA will look into soon