if it still works... ;)
Ah, those COBOL days. I cut my professional teeth on COBOL OS V1 and 2, multiple CICS A/TORs, VSAM and DB2 back in 1989.
I worked for a large Bank at that time and millions of transactions were being applied to millions of accounts each night.
Whilst the requirement is there to perform these processes surely, with developments already complete, it's cost effective to keep them running?
COBOL is still around simply because a) these processes are still functioning well and with integrity and b) they are too expensive to replace. And they won't be replaced until requirements are significantly altered to justify the huge costs of development.