The same can be said for Cobol and its relarionship with banking, but you will struggle to find anyone not categorizing cobol as legacy.

That's quite the non sequitur. The relationship you mention isn't why COBOL is legacy.

I'm not in banking so I don't know if banks write new business logic with Cobol or merely maintain existing systems. I would be very surprised, though, if modern web-based products are using Cobol, or fancy high-speed trading platforms, or big data-driven machine learning, etc.