whilst the point is made of say £500 allowances for a HKG trip, remember that the basic salary of BA longhaul cabin crew is c£14k after 8 years service.....so the allowances purely take their earnings up to a sensible level.....
However, the allowances are not taxed at the same rate, and while earnings are no longer as high as old contracts permitted, they still exceed in aggregate (a) competitors (both Europe, UK and US), (b) comparable high service industries, and (c) comparable safety-based roles in other industries.
The ability of crew to have a different decision from flight crew on whether to fly or not post-delay is also a quite ridiculous situation, reminiscent of 1970s union thinking.