I can understand why SS and others keep legacy software going. Way back when, no one worried about code longevity. It was simply assumed there'd be better hardware and better software coming while wages remained steady. Demand for software would be limited because few could afford the big iron hardware it needed. Well, we know what changes followed.
Until AI can do most programmning, coding costs will remain high, and old programs will still be used because they are costly to replace. There's some software I created in the '80s that not only remains in use, it's still adding new users, and I get a few $ for each purchase. I suspect AI will kill that off before much longer, but who knows?