This seems like a good opportunity for the XKCD modern infra diagram, where COBOL is holding up the financial system.
“Being “stable” and old, though, can create a paradox — a curse of success. Because when code runs nicely without anyone needing to check up on it, eventually people drift away. They stop looking at it, stop inspecting it. And that means they stop understanding how, precisely, it works.”
https://www.wealthsimple.com/en-ca/magazine/cobol-controls-your-money