BA has been around longer than the airlines used for comparison, and of course the staff may have been there for a longer time, and earn more as a result.
If I shop in Waitrose and see staff I have seen there for 20 or more years, then I don't expect them to be on the minimum wage, their cost to the company will be higher.
What I do expect for the money is superior service, and most of the time I get it. That is what BA has to do, and a lot of its' staff already do, deliver constant high quality products, then in the same way as Waitrose they will survive.
Quality is what BA has to concentrate on, consistently and relentlessly, without exception.
I love Easyjet and use them a lot but the sheer inexperience of a lot of the crews is blatantly obvious, leaving aside the undignified rush for seating
Attempting to compete with the newer carriers simply on price is useless, quality is what has to shine through - again and again and again, every single time, without exception.