We are a bank and DB2 z/OS 'is our heart beat' so to say.
Still, here we have more of PL/1, but that we have plenty and also new development.
I guess clients use either COBOL or PL/1.
New development tend to be 3-tier, still our batch processing is powerful and no plans to change that.
Traditional z/OS customers like banks will always have it, I have seen COBOL also in manufacturing (a car company) and telecommunication.