You raise a good point. I can read COBOL to get an idea of what it is doing and how it is structured takes a little getting used to, but so do most languages.
However, in my company (insurance) we have 3 COBOL systems (thanks to mergers) and one is on a rapid track for decommissioning not because it is COBOL, but because it is COBOL written in an obscure framework that was never popular and also coded in a non-English language, requiring knowledge of that language to understand the business logic. We can outsource some mainframe maintenance but not that one. The other mainframes will be around for at least the next 10/15 years.
However, in my company (insurance) we have 3 COBOL systems (thanks to mergers) and one is on a rapid track for decommissioning not because it is COBOL, but because it is COBOL written in an obscure framework that was never popular and also coded in a non-English language, requiring knowledge of that language to understand the business logic. We can outsource some mainframe maintenance but not that one. The other mainframes will be around for at least the next 10/15 years.