My take on this…

and therein lies (bolded part) the root cause to the answer to your question! BA was probably ahead of its competitors to adopt IT decades ago even before the internet when stuff was static and stored locally.

Slow bureaucratic processes, lots of out sourcing with lots of different teams and technologies decades later, you end up with an absolute mountain of tech debt, a mish mash of systems that most people who remain in the business don’t really have a grasp on what is actually at hand. Add in many poor attempts to patch it all up over the years, making it look nice to the end user (us!), without actually tackling the main underlying issues that are very costly to rip up and possibly prevent the airline from functioning if they did!

So then you have a choice to just continue with what is just about working and makes money vs causing even more deep rooted issues that could prove financially damaging. We all know BA is cost focused, therefore the choices they’ve made are to stick with what we have because it does work (to an extent, we have human intervention if needed) and there’s less risk, no one loses their job, we keep incrementally improving the user interface, everyone is semi content! From shareholder to Ft’er (sort of!)

All the while most know it isn’t really working or fit for purpose so now there’s a plan (another one) to reinvest, rewrite and fix. Whether they actually do this, remains to be seen. Judging by their app releases it seems they don’t really have great software management processes in place.

Meanwhile throughout this time, a very popular business model came along in the form of EasyJet, Ryanair etc who were far more agile and efficient, allowing them to adopt IT at a much later stage vs BA thanks to the internet and focused on utilising this as their primary source to make revenue, buy a seat, pay for a bag, pay to board early etc etc. Making sure they did this well on more modern technologies with very different investment strategies that could keep them agile.

As someone else eluded to, most experienced, talented people in tech won’t be that keen on working in corporate aviation as it simply won’t pay as well as a private, well funded scale up doing something sexy in AI!