MFCREW
Let's assume your figure of the cabin crew making savings of £150M is true. What was the cost of the strikes? £150M - ergo, according to your facts, the cabin crew have not yet contributed anything.
As it happens, I don't think your figures are correct, and the workgroup as a whole has indeed achieved its target. The dispute is ongoing though, because these savings were imposed because the union was just stalling and refusing to negotiate sensibly. This strategy has cost the cabin crew very dearly indeed, and I feel sorry for them. I think they genuinely have reason to be fearful for their long term careers now, but it did not have to be this way and they are powerless to turn back the clock now - as you rightly point out.
Like children not getting their own way, they can shout and scream and cause as much inconvenience as they like, the parent is always going to win - no ifs and no buts. This dispute will be over when the tantrum ends.