To echo Doppio above, I too rejoined Ryanair as a Capt last year having done a stint as a longhaul DEP at BA.
It’s not just about the money at all but I’m earning 60% more in net salary now I’m back at Ryanair, with only a v.small difference in company pension contributions. Time to command longhaul would have been 17 to 20 years. Bidline didn’t work for me as a pilot at the bottom of the seniority list and I hated night flying. I have more days at home per month now than I did at BA and my quality of life and bank balance is much healthier.
Many of those I joined BA with think along similar lines and I know of a couple of who have gone back to their previous employers.
Having said that, for some joining BA (longhaul) has been like winning the lottery. It’s still a good job but it all depends what your other options in life / career are. Be careful giving up an easy, well paid life elsewhere to have the ‘prestige’ of a British flag on the tail of your aircraft.