> Rewrites are hard. They're deceptively hard. They look like they should be easy, and they very much are not.

This is a major reason why so many financial/healthcare/insurance/government institutions still runs COBOL software on mainframes. Many times, you're looking at what is essentially a monolith (in many parts, but everything is connected in some way) that was 50+ years in the making.

Rewriting it is a huge and extremely expensive task, and had it not been because COBOL is considered a "bad language" by the young people, and thereby causing problems with recruitment, i'm guesssing the mainframe would be around for 100+ years to come.

As it is now, these companies are forced to migrate away from COBOL, and most companies in the financial sector would probably go for Java, which is posed to becomming the new COBOL.

If you start a career today as a young COBOL programmer, you will most likely have a high salary (for your career) for your entire work life.

The mainframe is certainly on the way out, but it's a big beast to move, and most "estimates" i hear from financial institutions is that they plan to migrate away in 10-30 years, and predicting what happens in 30 years is kinda pointless. Suffice to say that the Mainframe and COBOL is probably here for another 30-50 years.