I used to write COBOL back in the 70s. We (not me personally) were still writing it in the late 90s for a major UK bank. It's simple - anybody could turn their hand to maintaining it if the money was good. (Now MUMPS - that does require a lifetime of experience!)

Loudon Wainwright wrote a song about Y2K:
https://www.youtube.com/watch?v=8WY9kUm6TYM