They could potentially do it now with 3rd party handling and a clean sheet of paper like Level or CitiFlyer on short haul. But they only got here by ripping out the legacy cost base of old BA. In house handling, well paid staff who worked leisurely and unionsed hours. You can’t fly for £50 on that which is why it was all hived off, even Gatwick underwing was outsourced.
easyJet and Ryanair beat them at their own game.