The pension for new joiners is appalling. If you join BA in your thirties the projections show around 10k per year at 55.
But, that pension pot is yours to take with you if you change companies. With no bonding and a poor pension all that ties you is seniority and the "BA Way".
Without fleet expansion you may achieve a long haul command a few years before you retire. Then, you will be bottom of the Captains seniority list.
I wonder how many new starters are already wondering where they will take their 777/747 experience?