It's my understanding that many of the Indian body shops like Tata and Infosys do COBOL work. When I was an intern at Adobe, one of the other interns was Indian and had spent the last summer writing COBOL at Infosys. He was glad not to be doing that anymore, and I suspect engineers in India are looking to learn better-compensated skills just as in the U.S.
So I wonder if it's something like manufacturing in China - it's not just cheaper, it's that the expertise has moved.
You can't incentivize American programmers with a lot of experience by throwing money at them, when they retired ~50 years ago.
I signed up for a COBOL course at a state university around 2000, but dropped it without ever attending a class. I think they still had line printers.
At one point I was amused that there seemed to be a standard for object oriented COBOL...