Honestly, I am more suspicious that BA fanbois on an internet forum have an agenda. E.g., multiple posters here point to high BA cargo loadings despite the study actually correcting for "belly freight".

I mean, if you look at Norwegian's fleet, their load factors, and their seating density, it makes perfect sense they come out ahead. It's also no surprise that airlines like BA do badly. In fact, the year before, they didn't limit the study to certain TATL routes and had Qantas in the last place. Without having looked at Qantas' fleet, I imagined it was rankest lowest not due to the age of its fleet but primarily due to the low seating density on their planes.