I started to lose faith in BA's system five years ago when they failed to book/pay for a JAL connection in a return ticket bought long in advance. Then took 18 months to respond to the complaint and refund the extra charge. The recent logistical crises are massively exacerbated by IT incapacity and I'm simply no longer booking BA long haul, for the sake of:
1. being able to check in and
2. finding a plane and a crew there when I do.