My buddy's wife has a business degree and her first company had her learn Cobol for a couple of months (never had programmed before). I'm not sure where that went after the training, but apparently it's still a thing (this was only a few years ago).

We have several. Hiring is possible.

Hiring people with experience of the respective OS is more difficult.

C++ is not that similar to COBOL. COBOL is closer to Crystal Reports or SAP (ABAP). There are plenty of people with experience in those domains around today. Probably more than C++.