Well the archaic systems are getting older and older. From what I've heard it's almost impossible to get replacement parts for some of the computer systems that run airports/airlines.
In this case, for example, it wasn't the airline. It was Eurocontrol (https://www.eurocontrol.int)
Airline tech outages are just more visible than outages in other industries. Like manufacturing, etc. It doesn't make the news when all your manufacturing plants halt for 6 hours due to tech issues. Airlines could improve, sure, but pundit observations are usually off base. They are also dependent on systems they don't control, like ATC, TSA, Airport owned kiosks, and so on.
I'm not sure what the right answer is at that point. From dev-experience, I wouldn't want half-assed software directing flights. From ops-experience, I don't want software directing flights requiring specific hardware so you can just replace the hardware with easily available hardware.
I still believe we can create bug-free solution with modern toolset. It's a matter of zeros behind the project funding.