I think a lot of developers focus on learning newer technology stacks because they are hot and tend to pay more. But less popular doesn't mean it's not in demand.

I know 2 COBOL programmers who are being paid a ton of money because of critical banking systems running it and candidates are hard to find.

It's about perception. But the trend is what it is: https://trends.google.com/trends/explore?date=all&geo=US&q=r...